___are a major component of the membrane of
all cells.

Proteins and lipids are the major components of the cell membrane.

Explanation:

Depending on the membrane’s location and role in the body, lipids can make up anywhere from 20 to 80 percent of the membrane, with the remainder being proteins. While lipids help to give membranes their flexibility, proteins monitor and maintain the cell's chemical climate and assist in the transfer of molecules across the membrane.

this is math not biology xd

the correct answer is b