The correct option is D Glycocalyx
The cell envelope of bacterial cell consists of three layers - the outermost glycocalyx, the cell wall and the plasma membrane.
Glycocalyx is a thick, sticky layer surrounding the bacterial cell. It the could be a loose sheath (slime) or thick and tough (capsule).
The cell wall determines the shape of the cell and provides a strong structural support.
The plasma membrane is the innermost layer. It is selectively permeable.