Right choice is (a) m^2+3
To explain: The required answer is m^2+3. Now, by induction assumption, we have to prove 2+4+6+…+4(k+1) = (k+1)^2+3 also can be true, 2+4+6+…+4(k+1) = 2+4+6+⋯+(4k+4) and by the subsequent steps, we can prove that (m+1)^2+3 also holds for m=k. So, it is proved.