The correct option is
A e2x4(2x4−4x3+6x2−6x+3)+C∫x4.e2xdx
Applying by parts rule of integration,
x42e2x−42∫x3.e2xdx
Applying by-parts again, multiple times till the time powers in x in the integral vanishes,
x42e2x−2[x32e2x−32∫x2.e2xdx]
=>x42e2x−x3.e2x+3[x22.e2x−∫x.e2xdx]
=>x42e2x−x3.e2x+3x22.e2x−3[x2.e2x−∫e2x2dx]
=> x42e2x−x3.e2x+3x22.e2x−3x2.e2x+3e2x4+c
→e2x4(2x4−4x3+6x2−6x+3)+C