Which statement is true?

A. The function f(x) = cos(x) is an even function because its graph is symmetric about the origin.

B. The function f(x) = sin(x) is an odd function because f(-x) = -f(x).

C. The function f(x) = cos(x) is an odd function because f(-x) = f(x)

D. The function f(x) = sin(x) is an even function because its graph is symmetric about the origin.