The first true piece of sports equipment that man invented was the ball. In ancient Egypt, as everywhere, pitching(投掷) stones was a favorite children’s . But a badly thrown rock could hurt a child. Looking for something less erous to throw, the Egyptians made what were probably the first balls.
At first, balls were made of grass or leaves held together by vines (藤). Later they were made of pieces of animal skin sewed together and stuffed (塞满) with feathers or hay.
Even though the Egyptians were warlike, they found time for peaceful s. Before long they had developed a number of ball s, each with its own set of rules. Perhaps they played ball more for instruction than for fun. Ball playing was thought of mainly as a way to teach ’young men the speed and skill they would need for war.This selection says that the Egyptians played（）

A．many different s with balls
B．many different kinds of s
C．only one ball
D．different s with similar rules