When a cell does not divide, it enters
A. G₁ phase 
B. Quiscent stage
C. S-shape 
D. G₂ phase

Some cells in the adult animals do not appear to exhibit division (e.g., heart cells) and many other cells divide only occasionally, as needed to replace cells that have been lost because of injury or cell death. These cells that do not divide further exit G₁ phase to enter an inactive stage called quiescent stage (G₀) of the cell cycle.