With Regard to the Action of Hormones and Neurotransmitters on Cellular

Multiple Choice

With regard to the action of hormones and neurotransmitters on cellular receptors,which of these describes "amplification"?

A) When the extracellular concentration of a chemical messenger reaches a very high level,it overwhelms transporter molecules and the chemical floods into the cell.
B) Only hydrophilic first-messenger molecules can activate second-messenger molecules within the cell cytosol.
C) A single first-messenger molecule activates multiple second-messenger molecules,each of which activate thousands of enzymes.
D) Some cellular receptors have such low affinity for chemical ligands that it can require a million or more molecules to activate them.