C, because it protects the cell from the outside environment
The cell membrane functions as a selective barrier. We call these kind of membranes as differentially permeable or semi permeable membrane. It can decide what substances can pass in and out. Therefore it can surround the cytoplasm (which is the inside of a cell) to separate the cell's content from the surroundings.
Explanation:
Velocity refers to how fast the air is moving in distance per unit of time. While pressure is the measure of force applied on an area.
PDCAAS takes into account both the amino acid profile and the DIGESTIBILITY of a protein. PDCAAS is majorly used to indicate the quality of a protein. Protein digestibility refers to the ability of a protein to be broken down so that it can be absorbed. Protein digestibility depends mainly on the source of the protein.<span />
