Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
all even the professionals were interested in knowing. There was never so much as a landslide to bring the Fault to the attention of the connection. The population of the states affected was in places as low as five people per square mile! The land was so dry it seemed impossible that it could ever be used except for sheep-farming. It strikes us today as ironic that from the late '50s there was grave concern about the level of the water table throughout the entire area. the Rockies could anyone remember a series of rock slides as bad as Newspapers in the mountain states gave it a few inches on the front a dust volcano? Unusual, they knew, but right on the Kiowa Fault—could be. Labor Day crowds read the scientific conjectures with late summer some place in between. The dust volcano was on the face of it a more plausible theory. Still, it was only a theory. It had to be proved. As the tremors grew bigger, along with the affected area, as several towns including Edison were shaken to pieces by incredible earthquakes, whole bus- and plane-loads of geologists set out for Colorado, without even waiting for their university and government department to approve budgets. They found, of course, that Schwartzberg had been perfectly correct. They found themselves on the scene of what was fast becoming the most violent and widespread earthquake North America—probably the world—has ever seen in historic times. To describe it in the simplest terms, land east of the Fault was settling, and at a precipitous rate. Rock scraped rock with a whining roar. Shuddery as a squeaky piece of buckling and dropping, the earth trembled downward. Atop the new earth fissured and trembled, sliding acres at a time to fall, smoking, Dry earth churned like mud, and rock shards weighing tons bumped and rolled about like pebbles as they shivered and cracked into pebbles themselves. "It looks like sand dancing in a child's sieve," said the normally impassive Schwartzberg in a nationwide broadcast from the scene of disaster. "No one here has ever seen anything like it." And everywhere east of the Fault, to almost twenty miles away, the now-familiar lurch and steady fall had already sent several thousand Coloradans scurrying for safety. All mountain climbing was prohibited on the Eastern Slope because of the danger of rock slides from minor quakes. The geologists went home to wait. to add to the heaving chaos below. And the cliffs were higher every day as the land beneath them groaned downward in mile-square gulps. As the Fault moved north and south, new areas quivered into unwelcome down. They danced "like sand in a sieve" dry, they boiled into rubble. Telephone lines, railroad tracks, roads snapped and simply disappeared. Virtually all east-west land communication was suspended and the President declared a national emergency. and rapidly approaching the border of New Mexico to the south. Trinchera and Branson were totally evacuated, but even so the over-all death toll had risen above 1,000. The western borders of these states, and soon of the Dakotas and Oklahoma as well, were slowly sinking. On the actual scene of the disaster (or the scenes it is impossible the land shuddered downward in gasps and leaps. Springs burst to the floods, in the usual sense. The water moved too slowly, spread itself with no real direction or force. But the vast sheets of sluggish water and jelly-like mud formed death-traps for the countless refugees now streaming east. Perhaps the North Platte disaster had been more than anyone could take. 193 people had died in that one cave-in. Certainly by 7 October it had to be officially admitted that there was an exodus of epic proportion. Nearly two million people were on the move, and the U. S. was faced with a gigantic wave of refugees. Rails, roads and air-lanes were jammed with terrified hordes who had left everything behind to crowd eastward. for emergency squads which flew everywhere with milk for babies and dog food for evacuating pets. Gasoline trucks boomed west to meet the wrong side of the road. Shops left by their fleeing owners were looted by refugees from further west an American Airlines plane was wrecked as a hollow roar, a shriek and a deep musical vibration like a church bell. It was simply the tortured rock of the substrata giving way. The second phase of the national disaster was beginning. The noise traveled due east at better than 85 miles per hour. In its wake the earth to the north "just seemed to collapse on itself like day. "Not tremors, exactly," said the captain of a fishing boat which was somehow to ride out the coming flood, "but like as if the land wanted to be somewhere else." radio message delivered from a hastily arranged all-station hookup. "We of the gallant southland have faced and withstood invasion before." Then, as ominous creakings and groanings of the earth announced the approach of the tidal wave, he flew out of Montgomery half an hour before the town disappeared forever. One head of the wave plunged north, eventually to spend itself in Helena and Memphis felt the tremors. The tormented city shuddered through the night. The earth continued its descent, eventually tipping By morning it was plain that all of Arkansas was going under. Waves advanced on Little Rock at almost 100 miles an hour, new crests forming, overtopping the wave's leading edge as towns, hills and the thirst of the soil temporarily broke the furious charge. deluging Hobart and almost all of Greer County. Despite hopeful announcements that the wave was slowing, had virtually stopped after inundating Oklahoma City, was being swallowed up in the desert near Amarillo, the wall of water continued its advance. For the land was still sinking, and the floods were constantly replenished from the Gulf. Schwartzberg and his geologists advised the utmost haste in evacuating the entire area between Colorado and Missouri, from Texas to North Dakota. Lubbock, Texas, went under. On a curling reflex the tidal wave blotted rescuers on the cliffs along what had been the west bank of the Pecos River afterwards recalled the hiss and scream like tearing silk as the water broke furiously on the newly exposed rock. It was the most terrible sound they had ever heard. "We couldn't hear any shouts, of course, not that far away and with all were people down there. When the water hit the cliffs, it was like a collision between two solid bodies. We couldn't see for over an hour, because of the spray." Salt spray. The ocean had come to New Mexico. The cliffs proved to be the only effective barrier against the westward march of the water, which turned north, gouging out lumps of rock and tumbling down blocks of earth onto its own back. In places scoops of and about half a ton of vanilla cookies," he explained to his eventual rescuers. The barn, luckily collapsing in the vibrations as the waves bore down on them, became an ark in which they rode out the disaster. "We must of played cards for four days straight," recalled genial Mrs. Creeth when she afterwards appeared on a popular television But such lightheartedness and such happy endings were by no means typical. The world could only watch aghast as the water raced north under the shadow of the cliffs which occasionally crumbled, roaring, into the roaring waves. Day by day the relentless rush swallowed what had been dusty farmland, cities and towns. Some people were saved by the helicopters which flew mercy missions just ahead of the advancing waters. Some found safety in the peaks of western Nebraska and the Dakotas. But when the waters came to rest along what is roughly the present shoreline of our inland sea, it was estimated that over fourteen million people had lost their lives. No one could even estimate the damage to property almost the entirety

<question>:
Why was mountain climbing prohibited on the Eastern Slope during the time?

<options>:
A The rocks were shifting too fast and the paths could be confusing
B The flooding was too substantial
C They feared the danger of rock slides
D Rescue missions were too dangerous due to the sand storms

<answer>:

C