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

<passage>:
It is not really surprising that it took so long to figure out 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 The report was—no fire at all. The rising cloud was not smoke, but dust. Thousands of cubic feet of dry earth rising lazily on the summer air. Rock slides, they guessed certainly no fire. The Forestry Service interested. Seismologists were reporting unusual activity in the area, tremors too severe to be rock slides. Volcanic activity? Specifically, a dust volcano? Unusual, they knew, but right on the Kiowa Fault—could be. Labor Day crowds read the scientific conjectures with late summer lassitude. Sunday supplements ran four-color artists' conceptions of the possible volcano. "Only Active Volcano in U. S.?" demanded the headlines, and some papers even left off the question mark. It may seem odd that the simplest explanation was practically not Times ). The idea was not nearly so exciting as a volcano, even a lava-less one, and you couldn't draw a very dramatic picture of it. had never acted up before. It never sidestepped, never jiggled, never, never produced the regular shows of its little sister out in California, which almost daily bounced San Francisco or Los Angeles, or 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 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 chalk raked across a blackboard, the noise was deafening. The surfaces of the land east and west of the Fault seemed no longer to have any relation to each other. To the west, tortured rock reared into cliffs. East, where sharp reports and muffled wheezes told of continued buckling and dropping, the earth trembled downward. Atop the new cliffs, which seemed to grow by sudden inches from heaving rubble, dry earth fissured and trembled, sliding acres at a time to fall, smoking, There the devastation was even more thorough, if less spectacular. 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 pieces." But the band of scientists who had rallied to his leadership privately wondered if there would be any pieces. miles away, the now-familiar lurch and steady fall had already sent several thousand Coloradans scurrying for safety. life. Fields and whole mountainsides moved with deceptive sloth down, down. They danced "like sand in a sieve" dry, they boiled into rubble. Telephone lines, railroad tracks, roads snapped and simply disappeared. it is impossible to speak of anything this size in the singular) there was a horrifying confusion. Prairie and hill cracked open under intolerable strains as the land shuddered downward in gasps and leaps. Springs burst to the farmland and prairie, becoming a sea of mud beneath the sharp new cliffs which rose in rending line, ever taller as the land continued to sink, almost from Canada to the Mexican border. There were virtually no On 21 October, at Lubbock, Texas, there was a noise variously described 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 a punctured balloon," read one newspaper report. "Like a cake that's was a sigh and a great cloud of dust, and Oklahoma subsided at the astounding rate of about six feet per hour. seemed to rise a little like the edge of a hall carpet caught in a about the same moment. The tidal wave which was to gouge the center from the U. S. marched on the land. Helena and Memphis felt the tremors. The tormented city shuddered through the night. The earth continued its descent, eventually tipping 2-1/2 degrees down to the west. The "Memphis Tilt" is today one of the unique and charming characteristics of the gracious Old Town, but 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. great swirl. Whirlpools opened. A great welter of smashed wood and human debris was 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 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 The entire tier of states settled, from south to north, down to its eventual place of stability one thousand feet below the level of the new sea. Creeth carried and dragged his aged parents to the loft of their barn on the outskirts of town. His brother Geoffrey brought along the younger children and what provisions they could find—"Mostly a ham 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 along what is roughly the present shoreline of our inland sea, it was No one could even estimate the damage to property almost the entirety It was in such a cataclysmic birth that the now-peaceful Nebraska Sea came to America. Today, nearly one hundred years after the unprecedented—and happily unrepeated—disaster, it is hard to remember the terror and despair of contribute no small part to the nation's economy. Who can imagine what the middle west must have been like before the amelioration of climate brought about by the proximity of a warm sea? Carolina to the rich fields of New Mexico and the orchards of Montana, is directly ameliorated by the marine heart of the continent. Who today could imagine the United States without the majestic sea-cliffs in stately parade from New Mexico to Montana? The beaches the Appalachian Mountains, it is only a slight remnant of what it was. And though the Nebraska Sea today carries many times the tonnage of shipping in its ceaseless traffic, we have lost the old romance of scene. But this is by now no more than a petty annoyance, to raise a smile and the ferment of world culture. It would indeed seem odd to an American of the '50s or '60s of the last

<question>:
What could be meant by the Schwartzberg quote in the passage saying that, "It looks like sand dancing in a child's sieve."?

<options>:
A The rocks and dust were quickly mixing with water and creating mud.
B The rocks and dust were disappearing.
C The swirling dust and rocks were churning substantially.
D He was comparing the dust and rocks to a child by their minimal presence.

<answer>:

C