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

<passage>:
sense of excitement and satisfaction that he greeted the tall, dark, smooth-faced figure that came up the stairs and into the office shortly before noon. Many of the faces seemed familiar passengers. He was a short, corner for just a moment." removed an automatic pistol fitted with a silencer. Pointing it at the amazed customer, he fired four .22 caliber longs into the narrow chest. Then he made a telephone call and sat down to he would have to cover his tracks carefully. would be before his next client first to perceive the peculiar odor and to spot the immense gray hulk wallowing in the murky distance. Then the explosion had come, was in the second. The roar of the sinking ship was the last thing he heard for some time. Pembroke came as close to being a human being. When she left the hotel at midnight, Pembroke was quite sure that she understood his plan and in his pocket contained exactly His next thought was of food. He left the room and descended with him. Tomorrow might bring years of searching for a passion, for a cause, for a loyalty, Frank Pembroke had at last found his. his death, but it might also ensure peopled it. And Mary Ann would help him to save it. hungry, he began to study the probably. He also recognized several of the passengers. However, he made no attempt to speak to shooting out on the desert which others in the restaurant. walk. His situation could have been any small western American seacoast city. He heard the hiss going out anyway. He picked up Mary Ann at her told him that there were no living creatures anywhere but in fact that there was nothing to hunt and only a single target the city. Pembroke and Mary Ann took turns firing at the paper targets they had purchased. At twilight they headed back to the footprints would be left, Pembroke hopped off. Mary Ann her and that she had shot him. If necessary, she would conduct the authorities to the place where they had been target shooting, but would be unable to locate the spot where she had buried the body. Why had she buried it? Because at first she was not going to report the incident. one, but should be considerably safer. He headed slowly for the "old" part of town, aging his clothes against buildings and fences as he walked. He had already blacken his face. And he would look weary and hungry and aimless. Only the last would be a deception. walked through several small specialty shops. He tried to get the woman off his mind, but the to bother him. She was she might go to the police again, this time for vengeance. Twice during his wanderings Pembroke had seen the corpses that to her? Then he saw the weird little on each of its six limbs, and smiled up at him as he stared. "Can I help you, sir?" a middle-aged it would be simple enough to locate him if he were reported as being on the loose. There was a ground hog, had seven fingers left in Puerto Pacifico, and the counter. "What the hell was that?" Pembroke demanded. one of the—strangers?" "And if I were?" exodus would take place. Yet he was certain the first lap would be since no one he had talked was to leave shortly. If there was any but the most superficial examination, Pembroke would no doubt be discovered and exterminated. But since no one seemed "Well, they've got a point," knew where he was. But as he left the shop he began checking He headed for the nearest service station and asked for a when she recognized him. That admonished her in a whisper. "Walk on ahead." She obeyed. He followed. The "Okay, then where am I?" crowd grew thicker. They neared you are," the boy returned. "Pardon me, there's a customer," Pembroke watched him hurry To his surprise, the boy the little room. Then he saw that there was another entity in his presence "What is your name?" queried a metallic voice from a speaker on the wall. "Which situation's 'at?" minutes. Then he was told he giving with his perfect smile. "No getting out of here, is there?" "That's for sure," the boy said, walking away to wait on another customer. "If you don't like the place, you've had it." instructions. Then you will attack. In the meantime, serve us well." He stumbled out toward the docks, then looked about for Mary Ann. He saw her at last rectangular little man in his fifties named Spencer. He sat in a booth with three young women, in tears. Then she saw him. Waving frantically, she called his name all lovely, all effusive. The topic the woman persisted in her shouting. Sidling up to a well-dressed the ship, ignoring her. But still winked at him and snickered. sexy," the redhead said petulantly. "Just be yourself, gal," Spencer drawled, jabbing her intimately with a fat elbow, "and you'll qualify." "Me, me," the blonde with a feather cut was insisting. "What is wrong with me?" "Hell, no. But some poor punk's sure red in the face, I'll bet," the man-about-town said that," said Pembroke, snickering again as he moved away from the other. "And why not? Hey? Why not?" But the dolls had apparently lost interest in him. They got up one by one and walked out of the night he was deposited in a field tonic and moved over to Spencer's booth. "Okay if I join you?" himself, however, till the police how he had drifted far from the scene of the sinking of the "Sure," said the fat man. on a piece of wreckage, and had been picked up by a Chilean trawler. How he had then made his way, with "Wonder what the hell got into Spencer, peering at him suspiciously. "Maybe you've figured out where we are." "Your bet's as good as mine," the two demolished Pacificos that lay sprawled one atop the other in the corner. His watch said one-fifteen. The man from the FBI should arrive soon. There were footsteps on the stairs for the third time that man appeared at the door. His Spencer. "Look, Joe, what's the gag?" face was smooth, unpimpled, clean-shaven, without sweat on a "Well, so what?" demanded pistol solved his problem effectively. Pembroke tossed his third victim onto the pile, then opened a can of lager, quaffing the chair, both feet upon the desk. He would be out of business soon, once the FBI agent had got there. Pembroke was only in it to get the proof he would need to Spencer opened his mouth to protest, but saw with amazement that it was exactly this that had run in all the Los Angeles papers for the past week. The little ad that had saved mankind "Somebody's crazy around here," the fat man muttered after a few moments. "Is it me, Frank?" Spencer. Consider the men who went down with the ship. That was just part of the game." "What the hell are you sayin'?" asked Spencer in disbelief. the three babes? Ah, come on." "It's what you think that will determine what you do, Spencer. Pembroke rose and started out of the bar. A policeman entered and walked directly to Spencer's table. Loitering at the juke box, Pembroke overheard the conversation. "You Spencer?" "That's right," said the fat man sullenly. "Ah, hell! Nothin' wrong with you at all, and nothin'll make me say there is," said Spencer. "You're the guy, all right. Too bad, Mac," said the cop. Pembroke heard the shots as he strolled casually out into the brightness of the hotel lobby. While he waited for the elevator, he saw them carrying the body into the street. How many others, he wondered, had gone out on their backs during their first day that she was irrevocably in love

<question>:
Why does Pembrook shoot the man in the corner?

<options>:
A The man in the corner is one of the strangers.
B The man in the corner is an android sent by alien masters to facilitate an invasion of Earth.
C The man in the corner was an alien invader.
D The man in the corner came to kill Pembrook.

<answer>:

B