If the Sum of the External Torques Acting on an Isolated

Multiple Choice

If the sum of the external torques acting on an isolated system of particles is zero,it must be true that

A) the system can have no kinetic energy.
B) the angular momentum of the system does not change.
C) the system can have no angular velocity.
D) the system can have no linear velocity.
E) the angular momentum of the system must be continually decreasing.