I=∫(log2((x2+x+1sin([x]π))+sgn(x2+x+1)+1))dx is equal to (where [⋅] and sgn(⋅) denotes greatest integer function and signum function respectively)
(a) x+C
(b) cosx+x+C
(c) sinx+sgn(x2+x+1)+x+C
(d) −x+C
(a) x+C
(b) cosx+x+C
(c) sinx+sgn(x2+x+1)+x+C
(d) −x+C