Concept:Use substitution to simplify the integral into a standard form of sin.Explanation:Let I=∫1+x10x4cos(tan−1x5)dx.Put t=tan−1(x5).Then, 1+(x5)21⋅5x4dx=dt.So, 1+x105x4dx=dt.Hence, I=51∫costdt.This gives I=51sint+c.Substitute back t=tan−1(x5):I=51sin(tan−1x5)+c.Answer:5sin(tan−1x5)+c, where c is the constant of integration.Therefore, the correct option is A.