阅读理解。阅读下列短文, 从给的四个选项 (A、B、C和D) 中, 选出最佳选项。
【2014·日照模拟 】
Worldfamous violinist Itzhak Perlman was stricken with polio as a child.As a result，he wears braces on both legs and walks with the aid of crutches.At_concerts，getting on stage is no small achievement_for_him. He slowly crosses the stage until he reaches his chair. He lays his crutches on the floor，slowly undoes the clasps (扣环) on his legs，puts one foot backward and extends the other one forward.Then he bends down and picks up the violin，puts it under his chin (下巴)，nods to the conductor，and starts to play.
