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

<passage>:
Smith admitted he had made an error involving a few murders—and a few thousand years. He was entitled to a sense of humor, though, even in the Ultroom! HB73782. Ultroom error. Tendal 13. Arvid 6. Kanad transfer He reached into the pen, picked up the baby. As he did so the baby's knees hit the side of the play pen and young Laughton let out a scream—half from hurt and half from sudden lack of confidence in his new handler. But this did not deter Joe. He started off with the bright, teeth glinting in the sunlight. The man did not turn as the dog threw himself at him, burying his teeth in his leg. Surprised, the man dropped the screaming child on the lawn and turned to the dog. Joe seemed off balance and he backed up confusedly in the face of the going crazy. I can't say I dreamt it because there was Reggie with his bleeding knees, squalling for all he was worth on the grass—Oh, I don't even want to think about it." "We haven't lost Reggie, Nancy, remember that. Now why don't you try Nancy had taken a sedative and was asleep by the time Martin finished cleaning the .30-.30 rifle he used for deer hunting. He put it by the stairs, ready for use, fully loaded, leaning it against the wall next to the telephone stand. inside with the other man. "This is my new assistant, Dr. Tompkins." Martin and Tompkins shook hands. "The baby—?" Dr. Stuart asked. "You'd better get him, Dr. Tompkins, if we're to take him to the him, making idle comment until Dr. Tompkins came down the stairs with "Good-bye," Martin said, going to the door. Then he was nearly bowled over by the discharge of the .30-.30. Dr. Stuart crumpled to the ground, the baby falling to the lawn. Dr. Tompkins whirled and there was a second shot. Dr. Tompkins pitched forward on his face. The figure of a woman ran from the house, retrieved the now squalling "But there must be! I tell you I shot these men who posed as doctors. One of them was the same man who tried to take the baby this afternoon. They hypnotized my husband—" went to the door and opened it. "Say, Homer, take another look around the walk and the bushes. There's supposed to be two of them. Shot with a .30-.30." He turned and picked up the gun and examined it again. "Ever shoot a gun before, Mrs. Laughton?" Reggie." The sergeant nodded. "You were taking an awful chance, shooting at a guy carrying your baby, don't you think?" "I shot him in the legs. The other—the other turned and I shot him in the chest. I could even see his eyes when he turned around. If I hadn't pulled the trigger then ... I don't want to remember it." The patrolman pushed the door open. "There's no bodies out here but corner, eyes open, tongue protruding. He was dead. If we keep Reggie in the house much longer he'll turn out to be a tires screaming, bounced over the curb and sidewalk, straight toward the child and mother. Reggie, attracted by the sudden noise, looked up to see the approaching vehicle. His mother stood up, set her palms against her cheeks and shrieked. The car came on, crunched over the play pen, killing the child. The mother was hit and instantly killed, force of the blow snapping her spine and tossing her against the house. The car plunged on into a tree, hitting it a terrible blow, crumbling the car's forward end so it looked like an accordion. The men were thrown from the machine. "We'll never be able to prosecute in this case," the states attorney beer. Here's another report. This is his physical exam made not long afterwards. The man was in perfect health. Only variations are he had a scar on his leg where something, probably a dog, bit him once. And then a scar on his chest. It looked like an old gunshot wound, they said. Must have happened years ago." "That's odd. The man who accosted Mrs. Laughton in the afternoon was bitten by their dog. Later that night she said she shot the same man in the chest. Since the scars are healed it obviously couldn't be the same man. But there's a real coincidence for you. And speaking of the dogbite, the Laughton dog died that night. His menu evidently didn't agree with him. Never did figure what killed him, actually." "Any record of treatment on the man she shot?" "The men . You'll remember, there were two. No, we never found a trace of either. No doctor ever made a report of a gunshot wound that night. No hospital had a case either—at least not within several hundred miles—that night or several nights afterwards. Ever been shot with .30-.30?" The state attorney shook his head. "I wouldn't be here if I had." Laughton. Why did he pretend to be drunk?" funny business." "Guess you're right. Well, Mr. Smith won't think it's so funny when we hang criminal negligence or manslaughter on him. By the way, you've checked possible family connections?" driver's license. And there's no duplicate of that in Springfield, in case you're interested." The man who had laughingly told police his name was John Smith lay on it," he declared. "If you carry on any more we'll never get back to the Ultroom!" "I'm sorry, Tendal," the man on the cot said. "I didn't think—" "You're absolutely right. You didn't think. Crashing that car into that tree and killing that woman—that was the last straw. You don't even deserve to get back to our era. You ought to be made to rot get to thinking human life doesn't have any value. We wouldn't be here if it hadn't. But to unnecessarily kill—" The older man shook his head. "You could have killed yourself as well and we'd never get the job done. As it is, you almost totally obliterated me." Tendal 13 paced the length of the cell and back again, gesturing as he talked. "It was only with the greatest effort I pulled myself back together the poor thing by suggesting suffocation to it that night. "And speaking of that night, you remember we agreed I was to do the talking. But no, you pulled a switch and captured Martin Laughton's attention. 'I came as soon as I could, Martin,' you said. And suddenly I played a very minor role. 'This is my new assistant, Dr. Tompkins,' you said. And then what happened? I get shot in the legs and you get a hole in your back. We were both nearly obliterated that time and we didn't even come close to getting the child. "Still you wanted to run the whole show. 'I'm younger than you,' you said. 'I'll take the wheel.' And the next thing I know I'm floating in space halfway to nowhere with two broken legs, a spinal injury, concussion and some of the finest bruises you ever saw." These twentieth century machines aren't what they ought to be," Arvid 6 said. you, although it has me. They got to me right after the accident before I had a chance to collect my wits, dematerialize or "At great length. They had a psychiatrist in to see me. He was a queer fellow with the most stupid set of questions and tests I ever saw." "And you amused yourself with him." who came to the Ultroom to be transplanted to a younger body—and then sending him back beyond his original birth date—" Tendal 13 got up Tendal 13 walked briskly through the door, snatched Arvid 6 by the shoulders and shook him.

<question>:
Why didn't the man posing as Dr. Tompkins die?

<options>:
A He was able to escape and heal back in his time period
B He was wearing a bulletproof vest
C There was never a man named Dr. Tompkins
D The bullet in his leg caused a non-life-threatening injury

<answer>:

A