For which pairs of functions is f(g(x))=x?

A) f(x)=x^2 and g(x)=1/x

B) f(x)=2/x and g(x)=2/x

C) f(x)x-2/3 and g(x)=2-3x

D) f(x)1/2x-2 and g(x)=1/2x+2

For which pairs of functions is f(g(x))=x?

A) f(x)=x^2 and g(x)=1/x

B) f(x)=2/x and g(x)=2/x

C) f(x)x-2/3 and g(x)=2-3x

D) f(x)1/2x-2 and g(x)=1/2x+2