Q. Assertion (A) Some cells undergo -phase due to inactivation of cell cycle.
Reason (R) Cells at this stage remain metabolically active, but no longer proliferate.

 918  180 Cell Cycle and Cell Division Report Error

Solution:

Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
-phase is the permanent or temporary exit from the -phase. Cells in this phase remain metabolically active but do not proliferate unless called on to do so depending on the requirement of the organism.