Which of the following is the correct equation for the integral of f(x,y) over the curve C, where C is a closed curve?
A) ∫(-c) f(x,y) ds = -∫c f(x,y) ds
B) ∫c f(x,y) ds = -∫(-c) f(x,y) ds
C) ∫(-c) f(x,y) ds = ∫c f(x,y) ds
D) ∫c f(x,y) ds = ∫(-c) f(x,y) ds