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

<passage>:
Planet Stories Winter 1944. to get off Mars, because his trail was warm, and the Patrol thorough. then it was the final blast-off. were always jobs open. Meanwhile, he might as well enjoy himself, and it was safer to be seen with a companion than to be alone. He listened lazily to what the other was saying, leaning his tall, after them. Syme watched them through narrowed lids, feeling the glow of it was big. Kal-Jmar was the riddle of the Solar System. It was the only remaining city of the ancient Martian race—the race that, legends said, had risen to greater heights than any other Solar culture. The machines, the artifacts, the records of the Martians were all there, perfectly preserved inside the city's bubble-like dome, after God knew how many thousands of years. But they couldn't be reached. as it defied explosives and diamond drills. The field extended both above and below the ground, and tunneling was of no avail. No one knew what had happened to the Martians, whether they were the ancestors of the present decadent Martian race, or a different species. No one knew anything about them or about Kal-Jmar. In the early days, when the conquest of Mars was just beginning, Earth scientists had been wild to get into the city. They had observed it from every angle, taken photographs of its architecture and the robots that still patrolled its fantastically winding streets, and then they had tried everything they knew to pierce the wall. Later, however, when every unsuccessful attempt had precipitated a bloody uprising of the present-day Martians—resulting in a rapid dwindling of the number of Martians—the Mars Protectorate had stepped in and forbidden any further experiments And so he had made his first trip to Mars, and within twenty-four "Why. Are they really dangerous?" "They're unpredictable," Syme told him. "They're built differently, and they think differently. They breathe like us, down in their caverns where there's air, but they also eat sand, and get their oxygen that way." eat the damndest stuff. Lichens and fungi and tumble-grass off the deserts—all full of deadly poisons, from arsenic up the line to xopite. They seem intelligent enough—in their own way—but they never come near our cities and they either can't or won't learn Terrestrial. When the first colonists came here, they had to learn their crazy wilderness of fantastically eroded dunes and channels, laboring on sliding treads up the sides of steep hills only to slither down again on the other side. "Most of these gullies peter out gradually," said Syme, "but if we want almost-black sky visible from the floor of the gully, and shook his head. Neither Syme nor Tate ever had a chance to test the efficiency of their harpoon gun. They had traveled no more than five hundred meters, and "My God!" he said. "What are those?" Syme looked. "Those," he said bitterly, "are Martians." The natives, like all Martian fauna, were multi-legged. Also like all Martian fauna, they moved so fast that you couldn't see how many legs they did have. Actually, however, the natives had six legs apiece—or, more properly, four legs and two arms. Their lungs were not as large as they appeared, being collapsed at the moment. What caused the bulge a valve arrangement from the stomach and feeding directly into the bloodstream. Their faces were vaguely canine, but the foreheads were high, and the lips were not split. They did resemble dogs, in that their thick black fur was splotched with irregulate patches of white. These patches of white were subject to muscular control and could be spread out fanwise or, conversely, the black could be expanded to cover the white, which helped to take care of the extremes of Martian temperature. Right now they were mostly black. The natives slowed down and spread out to surround the wrecked sand car, and it could be seen that most of them were armed with spears, Martians. One Martian, who looked exactly like all the rest, stepped forward and The Martian leader looked at them enigmatically, then turned and started off. The other natives closed in on them, and they all bounded along under the weak gravity. half, and they then reached a branch in the gully and turned down ignored him. "We had our reasons for not doing so," the Martian said. ignore the obvious. We have not had a spoken language of our own for several thousand years." "You had nothing to give us," the Martian said simply. because you—had nothing to gain from mental intercourse with us?" "Yes." "No," the Martian interrupted him, "revealing the extent of our civilization would have spared us nothing at your people's hands. Yours is an imperialist culture, and you would have had Mars, whether you thought you were taking it from equals or not." The Martian looked at him appraisingly. "You already suspect. the Martians from knowing about it? Then he realized that the Martian Syme noticed that the other Martians had retired to the farther side of Mars to a planet with Terrestrially-thick atmosphere." "I think I see," Tate said thoughtfully. "That's been the ultimate aim all along, but so far the problem has us licked. If we solved it, then we'd have all of Mars, not just the cities. Your people would die out. You couldn't have that, of course." He sighed deeply. He spread his gloved hands before him and looked at them with a queer intentness. "Well—how about the Martians—the Kal-Jmar Martians, I mean? I'd dearly love to know the answer to that one." "Neither of the alternatives in your mind is correct. They were not a separate species, although they were unlike us. But they were not our ancestors, either. They were the contemporaries of our ancestors." "Several thousand years ago Mars' loss of atmosphere began to make itself felt. There were two ways out. Some chose to seal themselves into cities like Kal-Jmar our ancestors chose to adapt their bodies to the new conditions. Thus the race split. Their answer to the problem was an evasion they remained static. Our answer was the true one, for we progressed. We progressed beyond the need of science they remained its slaves. They died of a plague—and other causes. "You see," he finished gently, "our deception has caused a natural confusion in your minds. They were the degenerates, not we." "And yet," Tate mused, "you are being destroyed by contact with an—inferior—culture." "We hope to win yet," the Martian said. "Will our two races ever live together in amity?" The Martian lowered his head. "That is for unborn generations." He sights of the Martian's Benson gun, and suddenly the pent-up rage in Martian. It was like tangling with a draft horse. The Martian was astonishingly tear it out of the Martian's fingers. And all the time he could almost feel the Martian's telepathic call for help surging out. He heard the He put everything he had into one mighty, murderous effort. Every muscle fiber in his superbly trained body crackled and surged with power. He roared his fury. And the gun twisted out of the Martian's weapon and snapped a shot at the nearest Martian. The creature dropped all the while he was mowing down the massed natives in great swaths, seeking out the ones armed with Bensons in swift, terrible slashes, dodging spears and other missiles in midair, and roaring at the top of his powerful lungs. could have grabbed a spear or something, but—I just couldn't, not even to save my own life. I—I halfway hoped they'd kill both of us." Syme glared at him and spat, too enraged to think of diplomacy. He that shattered all his previous concepts of the verities in life, and didn't know what to do about it.

<question>:
What happened when the Martians initially split into two populations?

<options>:
A One population thrived and the other died out
B Both populations suffered as a result of the split
C Both populations eventually combined once more
D Both populations succeeded and thrived, but in very different ways

<answer>:

A