If \(b \ne 0,\) and \(1 - \dfrac{a}{b} > 3,\) which of the following must be true?

I. \(-a > 2b\)
II. \(a < 0\)
III. \(\dfrac{a^3}{b^3} < 0\)

A. I only
B. II only
C. III only
D. II and III only
E. I, II, and III

Answer: C

Source: Veritas Prep