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

<passage>:
rendezvous for death was plainly marked. The most dangerous is not the outlawed murderer, who only slays men, Darkness and the chill glitter of stars. Bo Jonsson crouched on a whirling speck of stone and waited for the man who was coming to kill There was no sound except the thudding of his own heart, the harsh rasp insulating material. He might be able to hear the footsteps of his murderer conducted through the ground. catfooting too softly to set up vibrations. A man could do that when with him, hunting him down. had to be a hunter, too, and track down the other man, before he died. Bo Jonsson's tongue was dry and thick in his mouth. He wanted to Maybe that was what had started it all—the death of Johnny Malone. revolution about the sun gives the departing ship a welcome boost, while minimizing the effects of Jupiter's drag. Moreover, being dense clusters, they have attracted swarms of miners, so that Achilles among the leaders and Patroclus in the trailers have a permanent boom town atmosphere. Even though a spaceship and equipment start out on his own—a race of individualists, rough and noisy and jealous, but living under iron rules of hospitality and rescue. The Last Chance on Achilles has another name, which simply sticks an "r" in the official one even for that planetoid, it is a rowdy bar where Guardsmen come in trios. But Johnny Malone liked it, and talked Bo Jonsson into going there for a final spree before checkoff and getting too fantangling civilized, except Venus, and I don't enjoy Venus." Johnny was from Luna City himself: a small, dark man with the quick nervous movements and dipped accent of that roaring commercial he didn't grate on Bo, they had been partners for several years now. one of Achilles' three live ecdysiasts with hungry eyes, and by some miracle found an empty booth. Bo squeezed his bulk into one side of the cubicle while Johnny, squinting through a reeking smoke-haze, dialed drinks. Bo was larger and heavier than most spacemen—he'd never have gotten his certificate before the ion drive came in—and was usually content to let others talk while he listened. A placid blond giant, himself bright, and always wanted to learn. Johnny gulped his drink and winced. "Whiskey, they call it yet! Water, and we've got to fortify ourselves for the trip. A bottle, a battle, and a wench is what I need. Most especially the wench, because I don't think the eminent Dr. McKittrick is gonna be interested in sociability, and it's close quarters aboard the Dog ." Bo kept on sipping slowly. "Johnny," he said, raising his voice to cut you want to talk like a jumper." "Because I am one at heart. Look, Bo, why don't you get over that inferiority complex of yours? A man can't run a spaceship without knowing more math and physical science than the average professor on "Suit yourself. If you don't want to uphold the honor of the Sirius Transportation Company—" Bo chuckled. The Company consisted of (a) the Sirius (b) her crew, himself and Johnny (c) a warehouse, berth, and three other part owners back in Luna City. Not exactly a tramp ship, because you can't normally space trip is expensive but in a few more years they'd be able to buy another ship or two, and eventually Fireball and Triplanetary would be getting some competition. Even the public lines might have to worry a little. Bo shook his head and watched his partner move off, swift in the puny to help, but Johnny faded along and edged up to the girl with his highest-powered smile. There were several other men standing around Bo sighed, feeling a bit lonesome. If he wasn't going to make a night A sharp noise slashed through the haze of talk and music Bo looked up. Johnny made some reply. Bo heaved up his form and strode toward the That was when it happened. Bo saw the little needler spit from the A spaceman, that. Knows how to handle himself in low-gee. It was the only clear thought which ran in the sudden storm of Bo's head. Bo had seen death before. That needle wasn't anesthetic, it was poison. soundless shower of chips. The bullet ricocheted flatly, heading off for outer space. No meteor gravel, that! Bo stood unmoving an instant, fighting the impulse to leap away. He was a spaceman, not a rockhound he wasn't used to this environment, and if he jumped high he could be riddled as he fell slowly down again. Sweat heatless dazzle blinding in his eyes. Fire crashed at his back. Thunder and darkness exploded before him. He lurched forward, driven by the impact. Something was roaring, echoes clamorous in his helmet. He grew dimly aware that it was himself. Then shouted beneath. Theoretically, one man can run a spaceship, but in practice two or three are required for non-military craft. This is not only an emergency reserve, but a preventive of emergencies, for one man alone might get too tired at the critical moments. Bo knew he wouldn't be allowed to leave Achilles without a certified partner, and unemployed spacemen available for immediate hiring are found once in a Venusian snowfall. Bo didn't care the first day. He had taken Johnny out to Helmet Hill his main thought a dull dread of having to tell Johnny's father when Bo returned to the transient quarters and dialed Valeria McKittrick. "Hadn't you heard?" asked Bo. He found it hard to believe she could got to get home. Can't you find somebody?" Bo shrugged, not caring much. "I'll circulate an ad if you want, but—" "Do so, please. Let me know." She switched off. Bo sat for a moment thinking about her. Valeria McKittrick was worth neat even without clothes. "Jonsson," said Bo. "Sorry to get you up, but I understood—" "Oh, yes. Are you looking for a spaceman? I heard your ad and I'm available." Bo felt his mouth gape open. "Huh? I never thought—" the slightest trace of accent, less than Bo's. "I thought I was stashed here too for the next several months." "How does a qualified spaceman happen to be marooned?" "I'm with Fireball, was on the Drake —heard of what happened to her?" Bo nodded, for every spaceman knows exactly what every spaceship is doing at any given time. The Drake while she lay in orbit, she had somehow lost a few hundred pounds of reaction-mass water from a cracked gasket. Why the accident should have occurred, nobody knew ... spacemen Bo had heard of it in the course of position, which'd make the trip home that much more expensive. Since we had one more man aboard than really required, it was cheaper to leave him behind the difference in mass would make up for the fuel loss. I Bo understood that kind of loyalty. You couldn't travel space without men who had it. Lundgard to be a Spacetech 1/cl with eight years' experience, qualified as engineer, astronaut, pilot, and any other of the thousand professions which have run into one. They registered articles and shook hands on it. "Call me Bo. It really is my name ... Swedish." Bo went at his share of the job doggedly, checking and re-checking and spent his time while waiting for Bo in swapping dirty limericks Sirius was loaded, inspected, and cleared. A "scooter" brought her three passengers up to her orbit, they embarked, settled down, and Bo relaxed against the thrust, thinking of Achilles falling away behind and a couple of minutes later he would be dead. Bo clamped his teeth together, as if he would grip consciousness in straining to break loose and kill him. to lie on naked rock while the enemy hunted him. Bo shuddered and the inside, scratched his ribs, and fallen dead. Next time he probably

<question>:
Who is the murderer for which Bo listens for footsteps?

<options>:
A Johnny Malone
B A Venusian
C An unknown person
D A crewmember from Fireball

<answer>:

D