Which of the following is the most important factor governing a cell's particular type of interaction with other cells
a. whether the cell is either an animal cell or a plant cell
b. the type of animal the cell came from
c. the location of the cell within an organism
d. the pattern of proteins on the cell's surface
e. whether the cell is either eukaryotic or prokaryotic

d. the pattern of proteins on the cell's surface

Explanation:

Cell to cell interaction is a very important phenomenon for a multicellular organism where the cells have to coordinate and cooperate to perform similar functions.

The cell interacts with another cell through chemicals which could act as signals to another cell.  

The cell to cell interaction depends on the recognition of another cell which is mediated by the proteins. The proteins are present on the cell membrane in the form of receptors and recognition proteins which could be arranged in the pattern. It is the pattern of the proteins which define the specificity to the recognition of the cell.

Thus, option-D is the correct answer.

as many times as you want

i think that it is plants