ANSWER
d. none of the above
EXPLANATION
The Law of Universal Gravitation states that:
[tex]F=G\cdot\frac{m_1m_2}{r^2}[/tex]
Where F is the force and r is the distance. Note that the force varies inversely with the square of the distance.
This means that the graph is definitely not linear, because the equation should have the form:
[tex]F=\alpha r+\beta[/tex]
where alpha and beta are constants.
It is not parabolic either, because in that case the form would be:
[tex]F=\alpha r^2+\beta r+\gamma[/tex]
Again, alpha, beta and gamma are constants.
And it's not circular, because we should have the square of the force too.
This said, the answer is none of the above.
Note: the graph is hiperbolic.
