4t^3 - 12t^2 - 4t + 12 = 0
(a) t = 1
4(1)^3 - 12(1)^2 - 4(1) + 12 = 0 4 - 12 - 4 + 12 = 0 0 = 0
Therefore, t = 1 is a solution.
(b) t = 2
4(2)^3 - 12(2)^2 - 4(2) + 12 = 0 32 - 48 - 8 + 12 = 0 -12 = 0
Therefore, t = 2 is not a solution.
(c) t = -1
4(-1)^3 - 12(-1)^2 - 4(-1) + 12 = 0 -4 - 12 + 4 + 12 = 0 0 = 0
Therefore, t = -1 is a solution.
(d) t = 0
4(0)^3 - 12(0)^2 - 4(0) + 12 = 0 12 = 0
Therefore, t = 0 is not a solution.
Therefore, the answer is (d) t = 0.