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

<passage>:
An hour later they surfaced about two hundred yards away from the usually exercises in a situation where the totally unexpected has occurred, and he and his two companions sat and stared in awed silence at the city a quarter-mile away. "Radio picked you up as soon as you entered the pipe," someone said. It a graceful movement of hand and arm he indicated the waiting city. a city—even a city like this one—in such surroundings. The men from the ship knew only the surface facts about this waiting geometric discovery. Theirs was the eleventh inter-planetary flight, and the previous ten, in the time allowed them for exploration while this planet was still close enough to their own to permit a safe return in their ships, had not spotted the city. But the eleventh expedition had, an hour ago, with just thirteen hours left during which a return flight could be safely started. So far as was known, this was the only city on the planet—the planet without any life at all, save tiny Three feet from the edge of the city Martin stopped and stubbed at the Wass watched him, and then shoved aside more sand, several feet away. After a time, Wass said, "Here, too. How far do you think it goes?" Martin shrugged. "Clear around the city? I'd like to know what it is—was—for." passed doors and arches and windows and separate buildings. They moved cautiously across five intersections. And they stood in a square Wass looked at him shrewdly. "Neither were the—well, shall we call lay ... and he thought everything outside the city seemed, somehow, He straightened his shoulders. The city was alien, of course, and that explained most of it ... most of it. But he felt the black city was something familiar, yet twisted and distorted. "Well," Wass said, his nose wrinkling a bit, "now that we're here...." "Pictures," Martin decided. "We have twelve hours. We'll start here. What's the matter, Wass?" There was a pause. Then Wass, defensively—"It's almost as if the city Wass turned away. Martin and Rodney started slowly down the wide metal saw—something—moving—" "We're trapped, we're trapped, they are—" "Shut up, Rodney! Wass, I'm only two sections from the edge. I'll check here." of this. Then—"We'll meet you in the middle of the city, where we Walking with Rodney, Martin heard Wass' voice, flat and metallic Wass' voice sounded startled. "Anti-radiation screen?" hundreds of thousands of years to activate such a screen." They reached the center of the city, ahead of the small, slight Wass, Wass' face, Martin saw, was sober. "I tried to call the ship. No luck." Wass nodded. "What else?" Wass stared down at the metal street, as if he could look through it. buildings surrounding the square. The corridor inside was dim and plain, and he switched on his flashlight, the other two immediately looks like a switchboard." The three advanced to the end of the central corridor, pausing before a "Is this it," Wass murmured, "or an auxiliary?" Martin shrugged. "The whole city's no more than a machine, apparently." Rodney furtively, extended one hand toward a switch. "No!" Martin said, sharply. That was one assumption they dared not make. Rodney turned. "But—" "No. Wass, how much time have we?" "The ship leaves in eleven hours." "Eleven hours," Rodney repeated. "Eleven hours!" He reached out for the switch again. Martin swore, stepped forward, pulled him back roughly. He directed his flashlight at Rodney's thin, pale face. "What do you "Going at it blindly, we'd probably execute ourselves." "We've got to—" "No!" Then, more quietly—"We still have eleven hours to find a way out." "Ten hours and forty-five minutes," Wass disagreed softly. "Minus the time it takes us to get to the lifeboat, fly to the ship, land, stow it, get ourselves aboard, and get the big ship away from the planet. "Make one move toward that switchboard and I'll stop you where you Wass moved silently through the darkness beyond the torches. "We all After a moment, Wass switched his flashlight back on. He said quietly, the city would take years." Wass laughed rudely. At length the incline melted smoothly into the next level of the city. Wass turned his light parallel with the floor, and then moved slowly in three lights, past openings in the occasional high metal partitions, holding his gun. "To the switchboard, Martin?" "Unless someone has a better idea," Martin conceded. He waited. But They began to retrace their steps along the metal street, back past then when they were walking toward it. The dream was gone again for But—The only city, so far as anyone knew, on the first planet they'd was in Wass' own interest. In a moment, all three were standing before Martin blinked. He thought how little time they had. He wet his lips. Wass' gloved hands fumbled awkwardly at a catch in the nearest section wouldn't grow there.... Or had they, once? "Don't, Wass!" Torchlight reflected from Wass' faceplate as he turned his head. "Why They stood before the switchboard again. Martin and Wass side by side, Rodney moved forward a little toward the switches. His breathing was loud and rather uneven in the radio receivers. Martin made a final effort. "Rodney, it's still almost nine hours to take off. Let's search awhile first. Let this be a last resort." Postpone and postpone until it's too late, and the ship leaves without us and we're stranded here to eat seeds and gradually dehydrate ourselves and God only knows what else and—" He reached out convulsively and yanked a switch. The radio receivers impersonally recorded the grating sounds of gradually—" Martin glanced at Wass, then started out of the switchboard room, not picking out shadowy, geometrical shapes, duplicates of the ones on the present level. "We'll find out," he said, "how many there are." Eleven levels later Rodney asked, "How much time have we now?" "Seven hours," Wass said quietly, "until take-off." "One more level," Martin said, ignoring the reference to time. "I ... think it's the last." "This is different," Wass said. "Built-in traps—" Wass turned, too, persistent. "But the planet was through with them." it off, Wass. We're looking for reservoirs, you know." Wass said, "All this had a purpose, once...." The three men, clad in their suits and helmets, grouped around the drifted and eddied directly beneath them. Then—"It wasn't.... Why did you close the hatch then?" "How deep," Wass said, from his safe distance. switches and blow yourself to smithereens?" Wass sighed and refused to meet Martin's gaze. Martin looked at him edge of the city. "I think we'll be all right," he called out, "as long "All right, Wass," Martin said quietly, as Rodney released the rope and "Wass!" There was no answer. The light faded swiftly away from the opening. and swirled about them until the purifying systems in their suits were plunged forward, to sink again to the knees, repeated the act, times without number. Then Wass broke his silence, taunting. "The ship leaves in two hours, Martin. Two hours. Hear me, Rodney?" Martin pulled his left foot from the sand and growled deep in his throat. Ahead, through the confusing patterns of the sparkling dust, Rodney stared. "Wass!" he shouted. "We've found a way out!" Their radios recorded Wass' laughter. "I'm at the switchboard now, Wass babbled incoherently into the radio for a moment, and then he He turned it on again when they reached the opening in the metal wall. Rodney nodded, jerkily. "He pulled three more switches. I couldn't

<question>:
How much time passed between the discovery of the city and Wass activating the switchboard?

<options>:
A 13 hours
B 10 hours
C 12 hours
D 11 hours

<answer>:

D