Which is a valid prediction about the continuous function f(x)?
A f(x) ≤ 0 over the interval (–∞, ∞).
B f(x) > 0 over the interval (–1, ∞).
C f(x) ≥ 0 over the interval [–1, 1].
D f(x) < 0 over the interval (0, 2).