The absence of rigid cell wall in animal cells favors which one of the following mechanisms?

The correct option is D Both A and B
The cell membrane is the limiting outer membrane in case of animal cells. The cell membrane is selectively permeable and allows transport of solvent and selected solute particles only. Thus, the animal cell can freely communicate with the environment and external medium as compared to the plant cell which is surrounded by a cellulosic cell wall. In plants, the purpose of the cell wall is to provide rigidity and mechanical support to the cell. In animal cells, certain functions like muscular contraction and nervous stimulation cannot be efficiently conducted if the animal cell is not in direct contact with the surrounding environment.

So, the correct answer is 'Both A and B'