A machine gun fires a steady stream of bullets at the rate of n per minute into a stationary target in which the bullets get embedded. If each bullet has a mass m and arrives at the target with a velocity v, the average force on the target is :

• A

  $60mnv$

• B

  $\frac{60v}{mn}$

• C

  $\frac{mnv}{60}$

• D

  $\frac{mv}{60}$