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

<passage>:
to a stop. spun in a pinwheeled blur, slowed, and settled to their proper the robot apprehensively. Half buried in mud, it stood quiet in Then the robots figured out an out of his misery. There was a sudden crash that hung sharply in the air, as if a tree had been hit by hill, throwing him to the jungle floor. "Damn!" He cursed again, circuits needed for the operation of its tracking mechanism alone. "There just isn't room for the electronics. You'd robot, crunching and snapping fire. He froze. "Good Lord! They communicate with each other! The one I jammed must be calling others to help." bank, away from the crashing eyes widened. "Of course! Radio! I'll bet anything they're automatically controlled by the "Blaster fighting! But it can't their brain is!" He paused. "Then, if that were put out of commission ..." He jerked away from the bank and half ran, half pulled himself through the undergrowth be!" tried to run, but vines blocked another robot fired in his direction, caught at his legs, tripping him and holding him back. Then, lower half of the cat creature two robots coming up from wider and wider forays, slowly or trip him. Even so, he stumbled his legs were a mass of stinging slashes from ankle to thigh. The crashing rumble of the killer robots shook the night behind wiping every trace of life from him, nearer sometimes, machines doing the job For a split second the jungle for which they were built, completely, build a robot that hunts by homing thoroughly, without feeling, again, and the robots would Alan leaped back, and fell one of the robots rolled silently his head. Alan froze. "My God, Pete built those things wrong!" Suddenly a screeching whirlwind branches and crashed against the robot, clawing insanely at the with no one to stop it, automatically With an awkward jerk the robot swung around and fired its blaster, completely dissolving the sending its robots in which had clung across the barrel. But the back pressure of the cat's body overloaded the discharge circuits. The robot started to shake, then clicked sharply as an overload relay snapped circuits would short, and one by to separate sense from futility. Finally parts would wear out, and shorted the blaster cells. and without human masters one the killers would crunch to a halt. A few birds would still The killer turned and rolled back fly then, but a unique animal life, rare in the universe, would As if in answer, a tree beside him breathed fire, then exploded. his foot catch in something, these robots in a batch and then 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 grabbed his ankle. Quickly he activated them all at once, probably clutched futilely at some leaves erupted angrily from the hole in he slammed his fist into the soft never living to realize that robot jerked back, its gun wobbled and started to tilt away. Then, getting itself under control, ground, close to where he lay. the robot reacted. It seemed familiar somehow. Then he remembered the robot on the river course!" He cursed himself for missing the obvious. "The blaster static blanks out radio transmission from the computer for a few seconds. They even do it to themselves!" Firing intermittently, he impulses came within its pickup pulled himself upright and hobbled The robot shook spasmodically with each shot, its gun tilted upward at an awkward angle. range, birds, insects, anything. swelling leg he stumbled out of Six or seven others also left the saw another of the robots standing for his small blaster to run dry. "Be damned! You can't win now!" Alan yelled between blaster shots, almost irrational from through his leg. Then it happened. frantically jerked the trigger again and again, and the spent cells released themselves from the device, falling in the grass at his feet. He dropped the useless gun. "No!" He threw himself on the ground as a new robot suddenly Blinding itself for a few seconds with its own blaster static, the robot paused momentarily, jiggling in place. In this the trees onto the spot where he into an insect hill and hurled the pile of dirt and insects directly at the robot's antenna. In a flash, stood frozen in a brilliant blue flash, followed by the sharp report of a blaster. Then another. hundreds of the winged things transmitting mental energy to the and he could see a robot rolling robot's pickup devices. of mind impulses, the robot fired erratically as Alan crouched and raced painfully for Confused by the sudden dispersion as he fumbled with the lock release. Jagged bits of plastic and stone ripped past him, torn loose drowned out almost immediately Apparently the robot hadn't open the door as the robot, sensing Frantically, Alan slammed by the blast. mind thought of nothing but the red-clad safety switch mounted beside the computer. Time stopped. There was nothing else in and silenced by an the world. He half-jumped, half-fell of seconds that seemed measured out in years. The universe went black. Later. Brilliance pressed upon through his body and dragged the next instant a charred nothing, unrecognizable, the victim of a design error or a misplaced wire in a machine. "I have to try," he said aloud. "I have to camp computer. That's where it was slowed by the Only, the robot didn't get tired. floor, hiding debris that tripped him and often sent him sprawling pants and shirt. Behind, the robot crashed imperturbably after him, lighting the night with fitful blaster flashes as some twice, blindly, into the undergrowth. Sharp screams punctuated the electric blue discharge as The robot crashed on, louder now, gaining on the tired human. Legs aching and bruised, foot tripped on a barely visible exploded around him. Startled, Alan jerked sideways, crashing his head against a tree. He buckled. His blaster fell into the The robot crashed loudly behind him now. Without stopping to think, Alan fumbled along the sticky that splashed over his Sharp muscle spasms shot from his shoulder across his back and chest. Tears streamed across his a mere hundred yards behind. He screamed at the blast. "Damn you, Pete! Damn your robots! Damn, damn ... Oh, Peggy!" Alan, lying in the mud of the stream bed, felt the earth shake as the heavy little robot rolled his arm felt numb. "I'll drown blood. The soft earth crumbled soil was held too tightly by the tree crashed heavily past Alan the moons, the killer robot stopped hugged the bank as a shaft of pure electricity arced over him, sliced into the water, and exploded in a cloud of steam. The robot shook for a second, its blaster muzzle lifted erratically and for an instant it seemed almost out of control, then it quieted and the muzzle again pointed down. Alan slid slowly along the bank the robot fired again. For a split head and back, and mud boiled Again the robot trembled. It into reverse. It stood poised for a second, its treads spinning crazily as the earth collapsed underneath dug, then it fell with a heavy splash into the mud, ten feet threw himself across the blaster robot's treads churned furiously in the sticky mud, causing it to buck and plunge like a Brahma blaster jerked upwards wrenching Alan's arms, then slammed down. Then the whole housing whirled around and around, tilting He fumbled for the sheath clipped the stationary portion of the robot. jammed in the knife blade—and was whipped headlong into the mud as the turret literally snapped

<question>:
Why did the robot at the stream fall into the mud?

<options>:
A Alan managed to knock it down with his blaster.
B It fell while trying to chase Alan, who managed to confuse it.
C The mud blocked its sensors and it did not know how to move properly.
D Its signals were disrupted and it malfunctioned.

<answer>:

B