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

<passage>:
Morgue Ship Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] He heard the star-port grind open, and the movement of the metal claws groping into space, and then the star-port closed. feeling all tight and wild inside himself. It went on for days. Moving the ship. Opening the star-port. Extending the retriever claw. Plucking some poor warrior's body out of the void. He didn't like it any more. Ten years is too long to go back and Two men. Rice and himself. Sharing a cozy morgue ship with a hundred suits, mouths open for air that had never been there in a hundred billion centuries. And they kept dancing without music until you extended the retriever-claw and culled them into the air-lock. That was all the war-glory he got. Nothing but the stunned, shivering silence, the memory of rockets long gone, and the shelves filling up "It's Lethla!" Rice retorted. Rice grabbed him by the shoulders. "Snap out of it, Sam. Think! Kriere—The All-Mighty—in our territory. His right hand man dead. That means Kriere was in an accident, too!" through the void picking up warriors and taking them back to the good green Earth. Grisly, yes, but it's routine. "As for Kriere—if he's anywhere around, he's smart. Every precaution is taken to protect that one." "But Lethla! His body must mean something!" "And if it does? Have we got guns aboard this morgue-ship? Are we a "We'll radio for help?" "Yeah? If there's a warship within our radio range, seven hundred thousand miles, we'll get it. Unfortunately, the tide of battle has Lethla. He's number ninety-eight. Shove me into shelf ninety-nine Lethla was alive. knew why. Involuntarily, Burnett moved forward. Lethla moved like a What in hell would Lethla be wanting aboard a morgue ship? Lethla half-crouched in the midst of the smell of death and the Lethla showed his needle-like teeth. "I thought it might be. Where's "I will." One hand, blue-veined, on the ladder-rungs, Lethla paused. Lethla came down. Like a breath of air on the rungs. "Interplanetary law declares it straight, Lethla! Get out! Only dead Lethla's gun grip tightened. "More talk of that nature, and only dead men there will be." He blinked. "But first—we must rescue Kriere...." "Kriere!" Rice acted as if he had been hit in the jaw. Burnett moved his tongue back and forth on his lips silently, his eyes lidded, listening to the two of them as if they were a radio drama. Lethla's voice came next: unexpectedly yesterday near Mars. We were forced to take to the life-boats, scattering, Kriere and I in one, the others sacrificing their lives to cover our escape. We were lucky. We got through the "We saw your morgue ship an hour ago. It's a long, long way to Venus. trick anyone. We knew you wouldn't know we were alive until it was too late and we controlled your ship. We knew you picked up all bodies for Lethla bowed slightly. "Who would suspect a Morgue Rocket of providing in years. "Sure," said Sam, smiling. "We'll pick him up." "No tricks," said Lethla. Burnett scowled and smiled together. "No tricks. You'll have Kriere on board the Constellation Lethla danced up, turned, waved his gun. "Come on." On the way up, Burnett thought about it. About Lethla poised like a white feather at the top, holding death in his hand. You never knew whose body would come in through the star-port next. Number ninety-eight was Lethla. Number ninety-nine would be Kriere. There were two shelves numbered and empty. They should be filled. And the hole-rim, stepped up, faced Lethla in a cramped control room that Chronometers, clicking, told of the steady dropping toward the sun at a slow pace. Burnett set his teeth together, bone against bone. Help Kriere escape? See him safely to Venus, and then be freed? Sounded easy, wouldn't be hard. Venusians weren't blind with malice. Rice and he could come out You may never catch up with the war again. The last trip! Yes, this could be it. Capture Kriere and end the war. But what ridiculous fantasy was it made him believe he could actually do it? "Now, where do you want this crate?" he asked Lethla easily. Lethla exhaled softly. "Cooperation. I like it. You're wise, Earthman." "There's your Ruler now, Lethla. Doing somersaults. Looks dead. A good Lethla with an intent scowl. Funny. This was the first and the last If Kriere could be captured, that meant the end of the war, the end of shelves stacked with sleeping warriors, the end of this blind searching. Kriere, then, had to be taken aboard. After that— Kriere, the All-Mighty. At whose behest all space had quivered like a smitten gong for part of a century. Kriere, revolving in his neat, water-blue uniform, emblems shining gold, heat-gun tucked in glossy jet holster. With Kriere aboard, chances of overcoming him would be eliminated. Now: Rice and Burnett against Lethla. Lethla favored because of his gun. Kriere would make odds impossible. Something had to be done before Kriere came in. Lethla had to be yanked off guard. Shocked, bewildered, fooled—somehow. But—how? where Lethla would send a bullet crashing into rib, sinew, sings and rips. And if you turn quick, catching it in the arm first, why— Kriere loomed bigger, a white spider delicately dancing on a web of stars. His eyes flicked open behind the glassite sheath, and saw the Constellation . Kriere smiled. His hands came up. He knew he was about to be rescued. Burnett smiled right back at him. What Kriere didn't know was that he way of drawing Lethla off guard, and it had to be but for the first time it was a good sound. And out of the star-port, at Sam Burnett's easily fingered directions, slid the long claw-like mechanism that picked up bodies from space. Lethla watched, intent and cold and quiet. The gun was cold and quiet, too. The claw glided toward Kriere without a sound, now, dream-like in its slowness. It reached Kriere. Burnett inhaled a deep breath. The metal claw cuddled Kriere in its shiny palm. Lethla watched. He watched while Burnett exhaled, touched another lever and said: "You know, Lethla, there's an old saying that only dead men come aboard the . I believe it." And the claw closed as Burnett spoke, closed slowly and certainly, all around Kriere, crushing him into a ridiculous posture of silence. There was blood running on the claw, and the only recognizable part was the head, which was carefully preserved for identification. That was the only way to draw Lethla off guard. The horror on Lethla's face didn't go away as he fired his gun. Fists made blunt flesh noises. Lethla went down, weaponless and claws come inside, and the star-port grind shut. Out of the red darkness, Rice's voice came and then he could see Rice's young face over him. Burnett groaned.

<question>:
Why did Lethla come aboard the morgue ship?

<options>:
A There were only two living people on the ship to overcome
B The ship had invisibility technology
C The ship had safe passage
D The ship had the specialized claw to retrieve Kriere

<answer>:

C