This is called a chemical bond.
Answer: A. Chemical signal
Explanation:
Chemical signal is the type of communication which coordinates actions between neighboring cells
.
This ability originated in single cells organisms and was essential for the evolution of multicellular organisms because after a cell receives a message, it is transferred across the plasma membrane and changes are brought about within the cell in response to this message.
I am pretty sure it is CD4 cell
Answer: the answer is evaperation :)