【单选题】

Questions 18 to 20 are based on the following passage.At the end of the passage, you will be given 15 seconds to answer the questions.

Now, listen to the passage.
This article is mainly aboutA．the weight of a whale’s brain.
B．the brains of geniuses.
C．the size of a person’s brain and his intelligence.
D．the intelligence of the elephant.