The force that is causing the circular motion $($the centripetal force $(F_C))$ of an object can be calculated using the following equation:

$F_C=\frac{m{v}^2}{R}$

where $m$ is the object's mass, $v$ is the object's velocity, and $R$ is the radius of the circular path. If the velocity changes by a factor of $3,$ the force changes by a factor of:

$6$

$5$

$12$

$3$

$1$

$9$