According to records at the guidance office, the mean GPA of all juniors is 3.45 and the mean GPA of all seniors is 3.62. Which of the following statements is true?

A. 3.45 is a statistic and 3.62 is a statistic.

B. 3.45 is a statistic and 3.62 is a parameter.

C. 3.45 is a parameter and 3.62 is a statistic.

D.3.45 is a parameter and 3.62 is a parameter.