Which of the following statements is true?
A. The brain of an aged person shrinks 5% every 10 years.
B. The brain of an adult person shrinks 2.5% every 10 years.
C. The cerebrospinal fluid of a person with 4 years of education may increase only slightly.
D. The cerebrospinal fluid of a person with 8 years of education may increase by 17.7 millimeters.