An Observer Located Outside Our Solar System, Who Monitors the Velocity

Multiple Choice

An observer located outside our Solar System, who monitors the velocity of our Sun over time, will find that the Sun's velocity varies by $\pm$ 12 m/s over a period of 12 years, due mainly to

A) Jupiter's gravitational pull.
B) Earth's gravitational pull.
C) variations in its brightness.
D) convection on the Sun's surface.
E) the sunspot cycle.