Find all zeros of the function f(x) = 2x4 + 3x3 + 16x2 + 27x - 18 and write the polynomial as a product of linear factors.
a. f(x) = (2x - 1)(x + 2)(x + 3)(x - 3)
b. f(x) = (2x + 1)(x - 2)(x + 3)(x - 3)
c. f(x) = (2x - 1)(x + 2)(x + 3i)(x - 3i)
d. f(x) = (2x + 1)(x - 2)(x + 3i)(x - 3i)