Mercury's Orbital Period Around the Sun Is 88 Days, and Its

Multiple Choice

Mercury's orbital period around the Sun is 88 days, and its synodic period (the time from one inferior conjunction to the next) is 116 days. How often do we observe a transit of Mercury across the face of the Sun?

A) It occurs every 88 days.
B) It occurs every 116 days.
C) It occurs much less frequently than once every 116 days because Mercury's orbit is inclined 7° from the plane of the ecliptic.
D) We never see a transit of Mercury because it always crosses the face of the Sun when it is on the opposite side from Earth.