What would be the coefficient of O2 in the balanced equation of Fe+ fe202

We are given with a function equal to f(x) = x^4. When the function is changed to -f(1/2x), the function changes to -f(1/2x) = (1/2 x)^4 equal to (-1/16 x^4). The graph of the function should be opening the opposite way and has  a narrower plot. answer is C