If function \(f(x)\) satisfies \(f(x)=f(x^2)\) for all \(x,\) which of the following must be true?

[VJesus12]

If function \(f(x)\) satisfies \(f(x)=f(x^2)\) for all \(x,\) which of the following must be true?

A. \(f(4)=f(2)f(2)\)

B. \(f(16)-f(-2)=0\)

C. \(f(-2)+f(4)=0\)

D. \(f(3)=3f(3)\)

E. \(f(0)=0\)

Answer: B

Source: GMAT Club Tests