Once upon a time, a rabbit wanted to cross a river but he could not swim. He had an idea. He saw a boss of crocodile swimming in the river. The rabbit asked the boss of crocodile, “How many crocodiles are there in the river?” The boss of crocodile answered, “We are twenty here.” “Where are they?” the rabbit asked for the second time. “What is it for?” the boss of crocodile asked.

“All of you are good, nice, gentle and kind, so I want to make a line in order. Later I will know how kind you are,” said the rabbit. Then, the boss of the crocodile called all his friends and asked them to make a line in order from one side to the other side of the river. Just then, the rabbit started to count while jumping from one crocodile to another: one … two … three … four … until twenty, and finally, he thanked all crocodiles because he had crossed the river.

The story mainly tells us about …
A. twenty crocodiles
B. the boss of the crocodile
C. a rabbit and twenty crocodiles
D. a rabbit and the boss of crocodile
E. the boss of the crocodile and all his friends