The cell membrane is also known as the plasma membrane. It is the outermost covering of:

The correct answer is Animal cells. The cell membrane, also known as the plasma membrane, is a vital component of all cells, regulating the passage of substances in and out. In animal cells, it serves as the outermost boundary, directly interacting with the external environment.

• Bacterial cells have a cell wall located outside their plasma membrane, providing structural support and protection.
• Plant cells also possess a rigid cell wall external to their plasma membrane, which gives them their characteristic shape and strength.
• Therefore, the plasma membrane is the outermost covering specifically for animal cells, making 'None of these' incorrect.