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

<passage>:
overrode his erstwhile genial features. I had a horrible suspicion. "Not again?" I said softly. Jery Delvin had a most unusual talent. He could detect the flaws in any scheme almost on sight—even where they had eluded the best brains that the U.S. copyright on this publication was renewed.] told him that he had been selected as the answer to the Solar System's greatest mystery, Jery assumed that it was because of his mental agility. MASTER SPY OF THE RED PLANET time to pierce the maze of out-of-this-world double-dealing. For Jery America that they were certain to be lovely in a Plasti-Flex brassiere without absolutely guaranteeing them anything, when the two security men came to get me. I didn't quite believe it at first, when I looked up and saw them, six-feet-plus of steel nerves and gimlet eyes, staring down at me, amidst my litter of sketches, crumpled copy sheets and unless maybe it was that hair dye that unexpectedly turned bright green after six weeks in the hair, but that was the lab's fault, not mine. So I managed a weak smile toward the duo, and tried not to sweat too profusely. "Jery Delvin?" said the one on my left, a note of no-funny-business in his brusque baritone. "... Yes," I said, some terrified portion of my mind waiting " You are Jery Delvin?" The man who spoke seemed more than surprised he seemed stunned. His voice held an incredulous squeak, a squeak which would have amazed his President in power, and not even that in matters of security. I managed to nod. He shook his white-maned head, slowly. "I don't believe it." "But I am, sir," I insisted doggedly. Baxter pressed the heels of his hands against his eyes for a moment, then sighed, grinned wryly, and waggled an index finger at an empty "I suppose you're wondering why I've called—" he started, then stopped short and flushed with embarrassment. I felt a sympathetic hot wave flooding my own features. A copy chief in an advertising company almost always reacts to an obvious cliche. Then, with something like a look of relief on his blunt face, he "Jery Delvin," he read, musingly and dispassionately. "Five foot eleven inches tall, brown hair, slate-gray eyes. Citizen. Honest, sober, civic-minded, slightly antisocial...." He looked at me, questioningly. "I'd rather not discuss that, sir, if you don't mind." "Do you mind if I do mind?" I couldn't have been more surprised had he announced my incipient maternity, but I was able to ask, "Me? For Pete's sake, why, sir?" Baxter looked me square in the eye. "Damned if I know!" 2 I stared at him, nonplussed. He'd spoken with evidence of utmost accused of a friendly josh, but—"You're kidding!" I said. "You must be. Otherwise, why was I sent for?" "what came out?" and said, without referring to it, "Jery Delvin, five foot eleven inches tall—" "Yes, but read me the part where it says why I was picked," I said, a "Uh-huh," Baxter grunted laconically. "It amuses you, does it?" The smile was still on his lips, but there was a grimness in the glitter of his narrowing eyes. "Not really," I said hastily. "It baffles me, to be frank." "If you're sitting there in that hopeful stance awaiting some sort of to make. IC had none to make. Damn it all to hell!" He brought a meaty fist down on the desktop. "No one has an explanation! All we know is that the Brain always picks the right man." I let this sink in, then asked, "What made you ask for a man in the first place, sir? I've always understood that your own staff represented some of the finest minds—" I only knew the problem!" "You sound disillusioned, sir," I interjected. He stared at me as though I'd just fallen in from the ceiling or somewhere. "Huh? Oh, yes, Delvin, isn't it? Sorry, I got carried away. over his slightly bucktoothed face, and we—Sir?" I'd paused, because he was staring at me like a man on the brink of apoplexy. I swallowed, and tried to look relaxed. After a moment, he found his voice. "To go on, Delvin. Do you recall that the government extended their trip by—Why are you shaking your head that way, sir?" "Because it's not true, Delvin," he said. His voice was suddenly old and tired, and very much in keeping with his snowy hair. "You see, the Space Scouts have vanished." getting letters and—" "Forgeries, Fakes. Counterfeits." "You mean whoever took the Scouts is falsifying—" "No. My misuse of tenses, deliberate misspellings. They take it out of an adult, especially an adult with a mind keen enough to get him into per day. Otherwise, they'd all be gibbering by now!" "And your men haven't found out anything?" I marvelled. Baxter shook his head. "And you finally had to resort to the Brain, and it gave you my name, form of an electronic brain, and even works on the same principle—can tell you that two and two make four. But can it tell you why? "Well, no, but—" relays and tubes, and out of the end of the answer slot popped a single "You got me!" I shrugged hopelessly. "However, since we have nothing else to go on but the locale from which Baxter nodded. "But that's impossible," I said, shaking my head against this disconcerting thought. "Yes," said Baxter. "That's what bothers me." nervous as hell. At least he was pacing back and forth amid a litter of half-smoked cigarette butts beside the gleaming tailfins of the "And when did you notice they were missing?" I asked, looking at the "Have you checked the storage tanks?" I asked. "Or is the cast-off water we lost." "Check the tanks," I said. source of new water for the tanks." "Uh-huh." I paused and considered. "I suppose the tubing for these tanks is all over the ship? In all the hollow bulkhead space, to take He stared, then frowned, and thought hard. "Yes, sir," he said, after a minute. "Even twice that, with no trouble, but—" He caught himself short. It didn't pay to be too curious about the aims of an automatically act the part. A shame, in a way." "The hell it is!" Baxter snapped. "Good grief, man, why'd you think the believe...." He waved me silent. "No connection at all, son. No, red tape was, well, involvement. Forms to be signed, certain factors to be considered, was impossible, Jery, my boy, to get anything done whatsoever without "But the danger. If you should pick the wrong man—" Baxter smiled. "No chance of that, Jery. We didn't leave it up to any committee or bureau or any other faction to do the picking. Hell, that situation, hand over the Amnesty, and pray." I had a sudden thought. "Say, what happens if two men are selected by the Brain? Who has authority over whom?" Baxter grimaced and shivered. "Don't even think such a thing! Even tapped the medallion gently "—in existence, Jery. So we couldn't have

<question>:
What clue did the water tanks and tubing give Jery?

<options>:
A An idea of how and when the boys went missing - probably during the night
B An idea of how much water was used during the trip
C An idea of how and when the boys went missing - probably via the tanks
D An idea as to whether or not the other man was lying

<answer>:

A