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

<passage>:
Sisko Rolf was fighting his greatest battle—to bring life to dying Mars. "Trapped us neatly," Rolf said through clenched teeth. "Tolled into Planet Patrol ship as he swung the deadly slimness of his rocket blast's barrel around to center on the fiery jets that betrayed the approaching outlaw flyers. Rolf swung the lax controls over hard as the bursts of fire revealed a looming barrier of stone dead ahead, and then he felt the tough skin In a slow sort of wonder Rolf felt the scrape of rock against metal, Down plunged the battered ship, downward ever downward. Somehow Rolf split open like a rotten squash, and Rolf felt himself Much later Rolf groaned with the pain of bruised muscles and tried to Rolf laughed. Without a pressure mask on the surface of Mars an light reached his eyes Rolf did not know—it had seemed an eternity of Rolf capped the solar torch. No use wasting the captive energy ahead, headquarters where renegade Frogs, Venusians from the southern sunken marshes of Mars, and Earthmen from dusty North Mars, concealed "They may have found the sunken seas of Mars," thought Rolf as he moved It was then, even as he snapped the release of his spinner and the nested blades spun free overhead, that he saw the slowly turning bulk of the cloud-swathed world, a tiny five mile green ball of a planet! The weird globe was divided equally into hemispheres, and as the tiny world turned between its confining columns a green, lake-dotted half alternated with a blasted, splintered black waste of rocky desert. As great shining gulf, Rolf could see that a broad band of stone divided the other half. Toward this barrier the spinner bore him, and Rolf was he could scout out the country beyond. it seemed to Rolf that he must be falling free jumbled mass of roughly-dressed stone slabs, from whose earth-filled crevices sprouted green life. So slowly was the spinner dropping that the blackened desolation of the through black dust, and he came to a stop. Deftly Rolf nested the rocks ahead. Rolf's slitted gray eyes narrowed yet more and his hand The voice had spoken in English! Rolf took a step forward eagerly and Rolf found himself staring, open-mouthed, at the sleek-limbed vision The girl laughed, a low liquid sound that made Rolf's heart pump She smiled again as Rolf's face slowly reddened. "Do not be ashamed," Rolf threw up the mental block that was the inheritance from his "Sorry," said the tall man as Rolf sprang easily from the ground to "She one of them?" Rolf's voice was low, but he saw Altha's lip twitch. "Sure." Rolf nodded. "Lost in equatorial wastelands—uh, about twenty Rolf followed the direction of the other's pale blue eyes. Overhead now lifted above the restless dark waters of a vast sea. Rolf realized with flies walking across a ceiling. "There," roared Tanner's voice, "is one of the seas of Mars." "One," repeated Rolf slowly. "You mean there are more?" Rolf felt new strength pump into his tired bruised muscles. Here lay he could lead the scientists of North Mars to this treasure trove of "Mark!" The girl's voice was tense. Rolf felt her arm tug at his sleeve A hundred paces away Rolf made the dark shapes of armed warriors as "The outlaws may capture," warned Tanner. "They have taken over the Rolf watched the column of barbarically clad warriors file out upon the "Right." Tanner's fingers bit into Rolf's arm. "Pray that the wind does Rolf's eyes slitted. There was something vaguely unhuman about those Then he knew. Above half naked feminine bodies, sinuous and supple utterly shoulderless, and beneath their furry pelts the ripples of "See!" Tanner's voice was muted. "Giffa, Queen of the Furry Ones!" Borne on a carved and polished litter of ebon-hued wood and yellowed her narrow earless skull. And the skulls of rodents and men alike linked together into ghastly festoons about her heavy, short-legged litter. Rolf raised his expoder, red anger clouding his eyes as he saw these Rolf and Mark Tanner came to their feet. Rolf's expoder rattled briefly like a high-speed sewing machine as he The expoder hammered in Rolf's heavy fist. Tanner smashed an elbow into Rolf's side. "Retreat!" he gasped. "Now where?" Rolf snapped another burst of expoder needles at the furry the heart of the Barrier. Rolf blasted another spurt of explosive shattered heart. An unseen furry shape sprang upon Rolf's shoulders Tanner's finger pointed. "Altha!" Rolf saw the graceful wings of the "The weasel heads won't follow us here?" asked Rolf. all of Mars so he created a world that would be all his own." Rolf laughed. "Like the pleasure globes of the wealthy on Earth." "Right." Tanner kept his eyes on the enlarging winged shape of Altha's "But," Rolf frowned thoughtfully, "what keeps Lomihi from crashing into "The island is the answer," said Tanner. "Somehow it blocks the force "The outlaws!" he cried. "They're after Altha." Rolf caught a glimpse of a sleek rocket flyer diving upon Altha's frail the old man pushing another crudely constructed glider toward the outer section of the wall swung slowly inward. Rolf sprang to his side. The older man's eyes were hot. He jerked at Rolf's hands and then Rolf pushed up and outward with all the strength of his weary muscles. near its center in a narrow strip of rocky gulch. A sudden thought made A man stood on guard just outside the flyer's oval door. Rolf lined up comrades. But if the outlaw saw him Rolf knew that he would be the about. Rolf pressed the firing button Rolf snapped his weapon overhand at the Frog's hairless skull. The momentarily. In that instant Rolf launched himself from the open They went down, Rolf swinging his fist like a hammer. He felt the Frog the guard's rifle expoder in his grasp the problem of escape from miles and more overhead. He knelt over the prostrate Venusian, using his belt and a strip torn A green bulge showed around the polished fuselage and Rolf pressed his This sledge was hammering relentlessly as Rolf sensed his first as he moved his arm. But Rolf had learned that his limbs were not By degrees Rolf worked his arm down to his belt where his solar torch Rolf heard voices from a distance and the answering triumphant bawling "Fire!" There was panic in the outlaw's voice. Rolf came to his knees not on the prisoners, and so the impact of Rolf's horizontally The outlaw was game. His fists slammed back at Rolf, and his knees jolted upward toward the patrolman's vulnerable middle. But Rolf smoke, and then the fingers of the outlaw clamped around Rolf's throat now he felt victory slipping from his grasp. Rolf swung, all the weight of his stocky body behind the blow, and the "Everything bongo?" Rolf wanted to know. "Glad of that." Rolf felt the warmth of her body so close beside him. A Rolf grinned up at her. "Need to?" he asked. Then they were over the Barrier and Rolf saw the last of the beaten Rolf snorted. "Shorty," he said disgustedly as they landed, but his arm

<question>:
What is so significant about this new area that Rolf is in?

<options>:
A It is abundant with water. It would be enough for all of Mars and the colonies.
B The presence of Altha, and her living here in secrecy.
C It is a secluded area, not yet touched by most other people.
D The miniature planet and the way it functions.

<answer>:

A