Final answer:
The type of protein that would be found totally within the membrane is referred to as 'Intramembrane.' Unlike transmembrane or cell-surface receptors which span the membrane, intramembrane proteins reside entirely within the membrane's hydrophobic region.
Step-by-step explanation:
The type of protein that would be found totally within the membrane is indicated by option D, Intramembrane. Transmembrane proteins, as the term suggests, span across the entire plasma membrane, having parts that are exposed on both sides of the membrane. Integral monotopic proteins are permanently attached to the membrane, but do not go all the way through. Cell-Surface Receptors, also known as transmembrane receptors, are integral proteins that span the plasma membrane for signal transduction processes. Therefore, they are not completely within the membrane as they have external and internal portions. In contrast, proteins referred to as intramembrane are located entirely within the hydrophobic region of the lipid bilayer, without parts protruding on either side.