A series of experiments was conducted in which rats of various ages were placed in a series of mazes and timed to see how long it took them to find their way out. In the first set of runs, the younger rats made their way out of the mazes an average of 30 percent faster than the older rats. Three days later, however, when the same rats were placed in the same mazes, the older rats were faster by nearly 40 percent.
Which of the following hypothesis best accounts for the findings of the experiments?
(A) A rat's sense of smell becomes less acute as it gets older.
(B) The older rats had been used in earlier experiments.
(C) Older rats have better-developed sensory memory, which allows them to "remember" the mazes three days later.
(D) Younger rats become frustrated when faced with repeated dead ends in a maze, while older rats do not.
(E) Older rats tire more easily than younger rats.
Oa will follow!