Read the paragraph and respond to the question: Learning how to ride a bike is no easy task. Most people learn as children and mount their first bicycle with training wheels mounted on the sides of
the back tires. Those training wheels eventually come off. When that happens, usually someone runs behind the bicycle, holding the back of the seat
as the rider learns to balance on two wheels. As the runner runs back and forth down the street, the rider eventually picks up on how to lean to stay
up on two wheels. Eventually, the runner lets go of the seat, and the rider rides off on his or her own.

What is the central idea of this passage?

A. Learning how to run behind a new rider
B. How to take training wheels off of a bicycle
C. Learning how to ride a two wheel bicycle
D. none of the above