Find torque and angular momentum

Question

A particle of unit mass moves in a force field given by 

F = (3t² - 4t)i + (12t - 6)j + (6t - 12t²)k          where t is time.

Find (a) the torque, and (b) the angular momentum about the origin at time t=2s assuming that at t=0s, the particle is located at the origin.