Answer
The earth's gravitational force on the sun is equal to the sun's gravitational force on the earth.
Work Step by Step
According to Newton's law of gravitation, the sun exerts a gravitational force of $F = \frac{G~M_s~M_e}{R^2}$ on the earth. Also, the earth exerts a gravitational force of $F = \frac{G~M_s~M_e}{R^2}$ on the sun.
Therefore, the earth's gravitational force on the sun is equal to the sun's gravitational force on the earth.