For which of the following functions does f(−k)=−f(k) for all real number values of x?	Choose the correct choice.
A) k^8  B) −k^6  C) k^5/k^7  D) k^9  E) k^4/k^2
f(-k) = (-k)^9 = -k*k^8   -f(u) = -u^9   k^9
<result>D</result>
For which of the following functions does f(−k)=−f(k) for all real number values of x?