An Experimental Psychologist Is Interested in Whether the Color of an Animal's

An experimental psychologist is interested in whether the color of an animal's surroundings affects learning rate. He tests 16 rats in a box with colorful wallpaper. The average rat (of this strain) can learn to run this type of maze in a box without any special coloring in an average of 25 trials, with a variance of 64, and a normal distribution. The mean number of trials to learn the maze, for the rats tested with the colorful wallpaper, is 11.
-What is the null hypothesis?

A) The rate of learning for the sample of rats tested with colorful wallpaper will be no different than the population of rats tested under ordinary circumstances.
B) The rate of learning for the sample of rats tested with colorful wallpaper will be faster than the population of rats tested under ordinary circumstances.
C) The rate of learning for the population of rats tested with colorful wallpaper will be no different than the population of rats tested under ordinary circumstances.
D) The rate of learning for the population of rats tested with colorful wallpaper will be faster than the population of rats tested under ordinary circumstances.