Which second degree polynomial function f(x) has a lead coefficient of 3 and roots 4 and 1?

Which second degree polynomial function f(x) has a lead coefficient of 3 and roots 4 and 1?

a. f(x) = 3x2 + 5x + 4
b. f(x) = 3x2 + 15x + 12
c. f(x) = 3x2 – 5x + 4
d. f(x) = 3x2 – 15x + 12