Answer :
Answer:
No net external torque acting on the system.
Explanation:
The law of conservation of angular momentum defines that "in an isolated system, the total angular momentum of a system remain constant if no net external torque acting on the system". The mathematical description is given by :
In an isolated system,
[tex]\tau=\dfrac{dL}{dt}[/tex]
[tex]\dfrac{dL}{dt}=0[/tex]
So, L = constant
So, the correct option is (B).