Final answer:
Phospholipids, cholesterol, and proteins contribute to the stability and fluidity of a cell's membrane. Phospholipids form the bilayer structure, cholesterol provides fluidity, and proteins serve as transporters and have various other functions.
Step-by-step explanation:
The components that contribute to the stability and fluidity of a cell's membrane include phospholipids, cholesterol, and proteins. Phospholipids are the primary component of the plasma membrane, forming a bilayer that is the basic fabric of the membrane. Cholesterol is embedded within this phospholipid bilayer and contributes to the fluidity of the membrane, allowing for flexibility and preventing the fatty acid chains from sticking together.
Proteins are also an integral part of the cell membrane, serving various functions including acting as transporters for substances entering and exiting the cell. Nucleic acids, on the other hand, are not involved in the structure of cell membranes but rather carry genetic information. Therefore, the correct answer to which components contribute to the stability and fluidity of a cell's membrane is A) Phospholipids, B) Proteins, and C) Cholesterol.