The impulse J is equal to the magnitude of the force applied to the cannonball times the time it is applied:

But the impulse is also equal to the change in momentum of the cannonball:

If we put the two equations together, we find

And since we know the magnitude of the average force and the time, we can calculate the change in momentum:
The answer is the option c. generator. Generator is a machine that
converts mechanical energy into electricity. The way it is made is
because the mechanical movement may be transformed in rotation of
magnets placed inside a coiled wire, and this induces the movement of
electrons through the coiled wire. As you know electricity is the flow
of electrons.