How Does Mercury Rotate, Relative to the Sun

How does Mercury rotate, relative to the Sun?

A) Mercury rotates relatively quickly, so that a solar day (from sunrise to the next sunrise) on Mercury is just a bit shorter than on Earth.
B) Mercury rotates in a retrograde direction; consequently, the Sun rises in the west each day and sets in the east.
C) Mercury turns the same side (Caloris Basin) toward the Sun at all times, much as the Moon turns the same side toward Earth.
D) Mercury alternately turns one side (Caloris Basin) toward the Sun at one perihelion and the opposite side toward the Sun at the next perihelion.