An apple falls from a tree because of gravitational attraction between the earth and the apple. If $F_1$ is the magnitude of force exerted by the earth on the apple and $F_2$ is the magnitude of force exerted by the apple on the earth,then:

• A
  $F_1$ is very much greater than $F_2$
• B
  $F_2$ is very much greater than $F_1$
• C
  $F_1$ and $F_2$ are equal
• D
  $F_1$ is only a little greater than $F_2$