Multi-choice problem: Continue writing the next sentence in this paragraph:

There's a person walking on stilts on a sidewalk where several cars are parked. He is demonstrating how to walk on stilts. he

Pick your answer from:
a). is using a walking stick to move back and forth on the sidewalk near a curb and railings..
b). is joined by two other men who also join him in the tutorial..
c). stops and takes a break..
d). demonstrates the trick using a real stilt..
b).