In animals, cell recognition:

a. involves only glycolipids.
b. is mediated by the lipid bilayer.
c. involves soluble proteins.
d. involves proteins in plasma membranes.

The correct answer is D.  involves proteins in plasma membranes.

Explanation:

Animal cells have several types of proteins embedded in their cell membrane. These proteins play an important role in the transport of molecules, cell recognition, and cell communication.  

Recognition proteins are a type of glycoproteins present in the plasma membrane that allow one cell of the body to recognize the other body cells by making contact with recognition proteins of other cells. Receptors proteins allow cell-cell communication by receiving extracellular proteins.

These proteins are important for proper growth and development of the cell. Therefore the correct answer is D.  involves proteins in plasma membranes.

i would have a lunch. it's one big package of food, making it one food. : p