Unlike most sports, which evolved over tim

问题：

Unlike most sports, which evolved over time from street games, basketball was (31) by one man to suit a particular purpose. The man was Dr. James Naismith, and his purpose was to invent a (32) game that could be played indoors in the winter.

In 1891, Naismith was an instructor at a training school, which trained physical education instructors for the YMCAs. That year the school was trying (33) up with a physical activity that the men could enjoy (34) the football and baseball seasons. None of the standard indoor activities (35) their interest for long. Naismith was asked to solve the problem by the school.

He first tried to (36) some of the popular outdoor sports, but they were all too rough. The men were getting bruised from (37) each other and (38) hit with equipment. So, he decided to invent a game that would incorporate the most common elements of outdoor team sports without having the real physical (39) , Most popular sports used a ball, so he chose a soccer ball because it was soft and large enough that it (40) no equipment, such as a bat or a racket to hit it. Next he decided (41) an elevated goal, so that scoring would depend on skill and accuracy rather than on (42) only. His goals were two peach baskets, (43) to ten-foot-high balconies at each end of the gym. The basic (44) of the game was to throw the ball into the basket. Naismith wrote rules for the game, (45) of which, though with some small changes, are still (46) effect.

Basketball was a(n) (47) success. The students (48) it to their friends, and the new sport quickly (49) on. Today, basketball is one of the most popular games (50) the world.

（40）（）

A. requested

B. used

C. required

D. took