ans is A
$$\int_{0}^{\pi } x^{^{2}} \cos x dx \\= x^2 \sin x ]_0^{\pi} - \int_0^{\pi} 2x \sin x \\= x^{^{2}} \sin x ]_0^{\pi} + 2x \cos x ]_0^{\pi}- \int_0^{\pi} 2 \cos x dx \\= x^{^{2}} \sin x ]_0^{\pi} + 2x \cos x ]_0^{\pi}- 2 \sin x ]_0^{\pi} \\=[\pi ^2 (0) -0] + 2[ \pi (-1)-0] -2[0-0] \\=-2\pi$$
Integral of a multiplied by b equals
a multiplied by integral of b
minus
integral of derivative of a multiplied by integral of b