Explanation: Cell membrane is a biological lipid bilayer that separates the interior part of every cell from its exterior. The main components of cell membrane include lipids, proteins and carbohydrate moieties that are attached to either lipids or proteins.
Cytoskeleton contains series of intercellular proteins that gives shape and provides support to a cell. Enzymes are proteins that catalyze biological reactions. Receptors are proteins found mostly on the surface of a cell.
The answer is C=territoriality This is so because Al's cat may have seen another cat in his 'home'. Cats don't like it when other cats trespass into their territory, so this is a way of marking it.
