Which of the Following Is an Example of Assortative Mating

Which of the following is an example of assortative mating?

A) A female sparrow chooses a mate because he attracts her by singing a different species' song.
B) A female mouse chooses a mate because he is the same color that she is.
C) A female sheep chooses a mate because he has previously mated with many females.
D) A female lizard chooses to mate with the first male she encounters.
E) A dominant male elephant mates with most females in a group, excluding other males from mating with the females.