What Do the Signal Molecules Do to Control Cell Division

What do the signal molecules do to control cell division in normal cells?

A) Growth factors tell a cell to divide, and growth inhibitors prevent division.
B) Growth factors tell a cell to get bigger, and growth inhibitors prevent growth.
C) Growth factors tell the cell's DNA to lengthen, growth inhibitors tell DNA to shrink.
D) Growth factors keep normal cells from growing too big, and growth inhibitors keep them from staying too small.
E) Growth inhibitors are a type of growth factor that keeps a cell from getting too big.