Which of the following quartic functions has x = –2 and x = –3 as its only two real zeros?

Since the zeros are x = -2 and x = -3, the factors of the quartic function will be (x + 2) and (x + 3). Therefore, the correct quartic function would have (x + 2)(x + 3) as its factors.

Expanding the factors, we get (x + 2)(x + 3) = x^2 + 5x + 6.
Therefore, the quartic function with x = -2 and x = -3 as its only two real zeros is f(x) = x^2 + 5x + 6.