Answer:
d. partially permeable
Step-by-step explanation:
The cell membrane is the cellular organelle that covers and bounds all cells. It forms a boundary around a cell, protecting all other organelles. The cell membrane, according to the FLUID MOSAIC MODEL, contains phospholipid bilayer, proteins etc.
The phospholipid (lipid) content of the cell membrane confers its ability to be SELECTIVELY OR PARTIALLY PERMEABLE upon it. It is said to be partially permeable because it allows the passage of some molecules/substances and blocks the passage of others.