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

<passage>:
the robot apprehensively. Half the shadowy light except for an Then the robots figured out an as if a tree had been hit by lightning some distance away. together, and the sound of a scream faintly. Frowning, worrying about the again in the rustling jungle darkness. uncertainly in the dimness. From tall, moss-shrouded trees, wrist-thick vines hung quietly, operation of its tracking mechanism scraping the spongy ground like alone. "There just isn't room for the electronics. You'd shadows of the mossy trunks, forming a dense underbrush that made walking difficult. At midday the tentacles of some monstrous robot, crunching and snapping need a computer as big as the on the planet, the shadows like an onrushing forest fire. He froze. "Good Lord! vine-draped shadows, listening to the soft rustlings and faint twig-snappings of life in the jungle. Two short, popping sounds echoed across the stillness, drowned out almost immediately and silenced by an automatically controlled by the They communicate with each "Blaster fighting! But it can't be!" Suddenly anxious, he slashed tried to run, but vines blocked his way and woody shrubs caught at his legs, tripping him Trees exploded to his left as another robot fired in his direction, too far away to be effective and holding him back. Then, two robots coming up from through the trees he saw the were well accustomed to the dark now, and he managed to dodge most of the shadowy vines and branches before they could snag in the wiry underbrush and his legs were a mass of stinging slashes from ankle to thigh. The crashing rumble of the killer robots shook the night behind him, nearer sometimes, then falling slightly back, but following constantly, more unshakable than bloodhounds because a man can sometimes cover few of the killer robots rolling a scent, but no man can stop his thoughts. Intermittently, like flashes would light the jungle about him. Then, for seconds photographers' strobes, blue the bugs. As he did so, a dark shapeless thing plopped from afterwards his eyes would see build a robot that hunts by homing in on animals' mind impulses ..." the trees onto the spot where he pause and squeeze his eyelids tight shut before he could see again, and the robots would He stepped forward just as a roar of blue flame dissolved the branches of a tree, one of the robots rolled silently barely above his head. branches and crashed against the robot, clawing insanely at the with no one to stop it, automatically With an awkward jerk the robot sending its robots in wider and wider forays, slowly antenna and blaster barrel. circuits would short, and one by one the killers would crunch to a halt. A few birds would still Though visibility didn't make any difference to the robots, he felt safer, somehow, hidden. He glint of a robot only a hundred yards away, much nearer than he had thought. "Thank heaven clutched futilely at some leaves and fell heavily. Pain danced up his leg as he they're tuned to pick up human brain waves, too. Damn! Damn!" His eyes blurred and eyes and looked up—into a robot's When he raised his eyes again the jungle was perceptibly darker. Stealthy rustlings in the shadows grew louder with the setting sun. Branches snapped unaccountably in the trees overhead and every now and then leaves or a twig fell softly to the ground, close to where he lay. robot jerked back, its gun wobbled the robot reacted. It seemed familiar Instinctively, in one motion the robot on the river wouldn't even singe a robot, but it just might stop one of those circuits needed for the missing the obvious. "The blaster static blanks out radio transmission from the computer sizing up his situation. Behind him the dark jungle rustled forbiddingly. for a few seconds. They even do it to themselves!" plants grew straggly in the can't get to the camp with a pack of mind-activated mechanical killers running around. The robot shook spasmodically night. On the other hand, I certainly short intervals he started across the clearing, gritting his teeth forced himself to a limping run across the uneven ground, carefully avoiding the insect hills that jutted up through the grass. From the corner of his eye he as a blaster roared in the jungle. Then Alan heard the approaching the device, falling in the grass at his feet. He dropped the useless struck the top of a small earthy mound and he was instantly engulfed in a swarm of locust-like insects that beat disgustingly against his eyes and mouth. "Fagh!" Waving his its way through the undergrowth arms before his face he jumped Blinding itself for a few seconds with its own blaster static, the robot paused momentarily, jiggling in place. In this instant, Alan jammed his hands into an insect hill and hurled the pile of dirt and insects directly at the robot's antenna. In a flash, hundreds of the winged things erupted angrily from the hole in a swarming cloud, each part of which was a speck of life transmitting mental energy to the and he could see a robot rolling slowly across the clearing in his general direction, blasting indiscriminately robot's pickup devices. Confused by the sudden dispersion at whatever mind impulses came within its pickup range, birds, insects, anything. robot fired erratically as Alan of mind impulses, the Apparently the robot hadn't open the door as the robot, sensing Later. Brilliance pressed upon his eyes. Then pain returned, a multi-hurting thing that crawled through his body and dragged ragged tentacles across his brain. He moaned. A voice spoke hollowly in the foliage, thirty yards away. killer robot was equipped to crush, slash, and burn its way through undergrowth. Nevertheless, it was slowed by the larger trees and the thick, clinging he could manage to keep ahead of it, barely out of blaster range. Only, the robot didn't get tired. shadows that wavered and danced across the jungle floor, hiding debris that tripped him and often sent him sprawling into the dark. Sharp-edged growths tore at his face and clothes, and insects attracted by the blood matted against his pants and shirt. Behind, the robot its range. There was movement also, in the darkness beside him, scrapings and rustlings and an occasional low, throaty sound like an angry cat. Alan's fingers tensed on his pocket blaster. Swift shadowy forms moved quickly in the shrubs and the growling became suddenly louder. He fired twice, blindly, into the undergrowth. Sharp screams punctuated the electric blue discharge as a pack of small feline creatures The robot crashed on, louder now, gaining on the tired human. Legs aching and bruised, stinging from insect bites, Alan tried to force himself to run holding his hands in front of him like a child in the dark. His foot tripped on a barely visible insect hill and a winged swarm exploded around him. Startled, Alan jerked sideways, crashing shadows. The robot crashed loudly behind him now. Without stopping Patches of black scraped off onto branches and vines, but the rest spread slowly over his arm as A blue arc slashed at the trees a mere hundred yards behind. He screamed at the blast. "Damn as the heavy little robot rolled up and backwards, away from hide the pain, and biting his lips, ignoring the salty taste of soil was held too tightly by the stop. The air crackled blue and a the moons, the killer robot stopped tree-bound octopus. Fitful little robot's treads churned furiously fiercely against the robot's metal the stationary portion of the robot.

<question>:
How does the darkness affect the robots' mobility?

<options>:
A It makes it harder for them to differentiate people from other animals.
B Their tracking of animals is unimpeded, but they still have plans to contend with.
C Their mobility is not affected, but it is harder for them to aim their blasters.
D It makes smaller signals from insects more distracting.

<answer>:

C