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

<passage>:
was at the prospect of seeing home once more. Ro was returning from the north. He had seen the great villages of thatched huts, the strange people who lived in these huts instead of in caves, and wore coverings on their feet and shining rings in their down. He was anxious to see his family again, his father and mother and all his brothers and sisters to sit round a fire with them at the entrance to their cave and tell of the wondrous places he'd visited. And, most of all, he wanted to see Na, graceful, dark eyed Na, whose to call him home. He breathed a sigh of relief as he reached the jungle's edge. Before great cliffs and the hills that were his home. His handsome face broadened into a smile and he quickened his pace to a trot. There was no need for caution now. The dangers on the plain were few. The sun beat down on his bare head and back. His red skin glistened. His thick black hair shone healthily. Mile after mile fell behind him. His long, well muscled legs carried him swiftly toward the distant hills. His movements were graceful, easy, as the loping of Shee, the great cat. Then, suddenly, he faltered in his stride. He stopped running and, the cliffs. Ro exclaimed his surprise, then his rage. His handsome face was grim as mouth furry face and twitching tail. The Oan, however, was too intent on his prey to notice Ro at first, and when he did, it was too late. Despite his frantic contortions, the stone caught him in the side. His ribs and backbone cracked under the blow. He was dead before he struck the ground. With hardly a glance at his fallen foe, Ro ran on to meet the girl. She eyes were wet with gladness. Warm tears ran down Ro's arm. Finally Na lifted her beautiful head. She looked timidly at Ro, her with women but he smiled instead. "You're home," breathed Na. cover of night, we were forced to leave the caves. One by one we went, and those of us who lived still travel alone." Ro groaned aloud as Na finished her tale. His homecoming was a meeting Surely he didn't fall to the Oan?" "He had no chance to fight," Na answered. "Two of your brothers died with him on that first morning." Ro squared his shoulders and set his jaw. He wiped a hint of tears from his eyes. "Then there will be more to kill," answered Ro without turning. Na smiled. Ro was angry, but anger did not make him blind. He would "You say they came from a place called Earth?" Ro asked Na in wonder. clasped on Na's wrist. "All men will know now that you are the mate of Ro," he whispered. And he kissed her, as was the custom of his tribe when a man took a wife. prolonged farewell. They would be together soon—on the far side of the He had lived in the cliffs all his life, and had made many perilous climbs, but never one on so dark a night. It seemed an eternity before he rested at the bottom. Feeling his way cautiously, he moved toward the camp. He could sense prickled. He prayed he wouldn't be seen. An alarm now would spoil his plan. the night. Ro could see his large ears, hear his twitching tail. In a moment the beast would stumble over him. Like a phantom, Ro arose from his crouch. The rat man was startled, frozen with fear. Ro drove his right arm around. The stone in his hand fell, lowered it noiselessly to the ground. Breathing more easily, Ro moved on. He reached the edge of the small heaps. They would be the slumbering rat men. Ro suppressed an urge to spring amongst them and slay them as they slept. He lay flat on his stomach and inched his way ahead. It was slow work, but safer. When a sound reached his ears he drew himself together and feigned sleep. In the dusk he appeared no different than the others. His chest was scratched in a thousand places when he reached the far side, but he felt no pain. His heart was singing within him. His job was almost simple now. The difficult part was done. Ro was more confident as he moved to untie the others. He worked more When they were ready, Ro signaled the four white people to follow him. something to one of the men. Ro turned and glared at her through the told them. "After a short while, we will meet Na." "Who is Na?" asked the girl. "She is the one I have chosen for my mate," Ro answered. should have met them minutes ago. Then he gave a glad cry. Squinting ahead he saw an approaching figure. shoulders was a girl. Ro's body tensed and quivered. A low growl issued from deep in his throat. He charged forward. The Oan saw him coming and straightened, allowing the girl to fall. He set his twisted legs and bared his fangs. The fur on his back stood out Ro struck his foe head on. They went down in a frenzied bundle of fury. strength, Ro tore it away before it could tighten. Ignoring the Oan's slashing teeth, the young Martian pounded heavy fists into his soft stomach. Suddenly shifting his attack, Ro wrapped and lay still. Ro dismounted the limp body. His face wore a wildly triumphant expression. It changed as he remembered the girl. He ran to her side. smiled as she recognized Ro. The young Martian breathed a sigh of relief. Ro gathered the girl in his arms. He spoke softly to her to help her When she had recovered from her shock, the small group traveled on. Ro a cleverly concealed cave. "We will stay here," he told the others, "until we are ready to attack Ro smiled. "We will speak of that when it is dawn again," he said with his thoughts. "Now we must rest." He sat in a corner of the cave and leaned back against the wall. His Ro introduced himself and Na. Ro sighed. Ro slipped his arm about Na's shoulder and drew her closer. With their heads together they slept. Ro awakened with the dawn. He was startled to find that Na had left his side. He rose quickly and strode to the mouth of the cave. Na met him at the entrance. She was returning from a clump of trees well provided for." "You will make no mate at all," Ro said sternly, "and there will be no table if you wander off. Your next meeting with the Oan may not be so fortunate." He glared at her for a moment, then smiled and helped her with her burden. The others in the cave awakened. Ro noticed that Charlotte had slept beside Carlson, but moved away shyly now that it was daylight. He noticed, too, that Grimm was seeing the same thing and seemed annoyed. Ro smiled. These young white men were no different than Martians where Ro sprang to his feet to tower above the man. His handsome face was twisted in anger. Grimm climbed to his feet and backed away. Ro advanced on him, his fists clenched. The old man also rose. He placed a restraining hand on Ro's arm. Ro turned quickly. "What is it?" he demanded. Ro laughed. When they had detailed their plan, the party left the cave. Ro led them "We leave you here," said Ro to the professor. "Na will lead you to the Ro looked at Na for a long moment before they parted. He grew very He turned to Carlson. The young Earthman was looking at Charlotte in much the same way. "Come on," Ro said. "If we spend the rest of the morning here, the Oan will try some strategy of their own." Carlson seemed to come out of a trance. He swung around to trail Ro up be trapped. They would die under a hailstorm of rock. "You would have liked a more tender goodbye with Charlotte," Ro said to Carlson as they worked. "Was it fear of Grimm that prevented it?" Carlson straightened. He weighed Ro's words before answering. Finally Ro seemed puzzled, then he laughed. "Last night I thought that we on Mars are backward. Now I'm not so sure. When we find our mates here, we take her. There is no one to

<question>:
When did Ro marry Na?

<options>:
A His second day back
B He had not yet
C After he freed the white men
D His first night back

<answer>:

D