Which of the Following Is Probably the Main Factor Responsible

Multiple Choice

Which of the following is probably the main factor responsible for the phenomenon of density- dependent inhibition?

A) a local accumulation of growth- inhibiting factors
B) cells' innate ability to "sense" when the organ of which they are a part has no need for additional cells
C) physical contact of cell- surface proteins between adjacent cells.
D) a local deficiency of nutrients