option A will be correct
integration of sin^m * cos^n dx
if(m & n both are even integers)
then [(m- 1)(m -3)(m-5)....1(n -1)(n -3)(n -5)...1/(n+m)(n+ m -2)(n +m -4)...1]*pie/2
else [(m- 1)(m -3)(m-5)....1(n -1)(n -3)(n -5)...1/(n+m)(n+ m -2)(n +m -4)...1]* 1