Biology

The correct answer is A.Nucleic Acids.

Explanation:

Cell membranes are primarily composed of lipids (especially phospholipids), proteins, and carbohydrates. Here's a breakdown of their roles:

1.Lipids (mainly phospholipids and cholesterol) form the bilayer structure of the membrane, providing a barrier and contributing to membrane fluidity.

2.Proteins are embedded within or attached to the lipid bilayer and serve various functions such as transport, signaling, structural support, and enzymatic activity.

3.Carbohydrates are often attached to proteins (glycoproteins) ...