A principal was buying T-shirts for his school's chess club and found that the total cost
in dollars could be found by the function f(x) = 9x + 19, where x is the number of
members in the club. If there are at least 8 members on the team but not more than
11, then which of the following statements describes the function?

A. The value of x must be a whole number between 8 and 11 and the value of f(x) must
be a whole number between 72 and 99.

B. The value of x must be a whole number between 8 and 11 and the value of f(x) must
be a whole number between 91 and 118.

C. The values of x and f(x) must both be whole numbers between 91 and 118.

D. The values of x and f(x) must both be whole numbers between 9 and 19.