JEE Math Practice Question

If S1 and S2 are respectively the sets of local minimum and local maximum points of the function, ƒ(x) = 9x4 + 12x3 – 36x2 + 25, x $$ \in $$ R, then :

1. A.S1 = {–1}; S2 = {0, 2}
2. B.S1 = {–2}; S2 = {0, 1}
3. C.S1 = {–2, 0}; S2 = {1}
4. D.S1 = {–2, 1}; S2 = {0}