Consider the arithmetic sequence. -9, -2, 5, 12, . . .

Given that the sequence is represented by the function f(n), what are the values of f(1) and the common difference?

A.
f(1) = -2
Common difference : -7
B.
f(1) = -9
Common difference : 7
C.
f(1) = -9
Common difference : -7
D.
f(1) = -2
Common difference : 7