Answer:
Answer is D - cAMP.
Explanation:
cAMP is a small molecule that functions as an intracellular signaling molecule - a second messenger. The first messenger would be the thing that activated the GPCR (e.g. a hormone). The GPCR is a signal transducer (converts extracellular signal to intracellular signal). Once activated, the GPCR activates adenylate cyclase which can be called a signal effector - it is an enzyme that produces cAMP.
Water molecules consist of 2 Hydrogen and 1 Oxygen atom. They are bonded by a polar covalent bond, meaning the electrons shared by the covalanet bonds are not evenly distributed. Oxygen is more electronegative than Hydrogen and will pull the electrons from its bonds with Hydrogen closer to itself. Thus results in a partial positive dipole on the Hydrogen of the water molecule and a partial negative dipole on the Oxygen of the water molecule. These partial charges allow water to hydrogen bond with one another through a process called cohesion.
