The correct option is B (y+1)(y+4)(y+6)(y−1)
(y2+5y)(y2+5y−2)−24
Let (y2+5y) be a
a(a−2)−24
=a2−2a−24
=a2−6a+4a−24
=a(a−6)+4(a−6)
=(a−6)(a+4)
Resubstituting the value we get,
(y2+5y−6)(y2+5y+4)
=(y2+6y−y−6)(y2+4y+y+4)
=[y(y+6)−1(y+6)][y(y+4)+1(y+4)]
=(y+6)(y−1)(y+4)(y+1)