Caffeine is an inhibitor of phosphodiesterase. therefore, the cells of a person who has recently consumed coffee would have increased levels of
a) phosphorylated proteinsb) campc) adenylyl cyclased) activated g proteins

B) cAMP

Explanation:

Phosphodiesterase is an enzyme that breaks a phosphodiester bond, for example in molecules such as cAMP and cGMP. So, phosphodiestarases are  are regulators of signal transduction: regulate the duration of signaling pathway.

Caffeine is  central-nervous-system stimulant and the mechanisms of its action usually are: mobilization of intracellular calcium or inhibition of specific phosphodiesterases.

did you fail the test? xd

a physical change is being made.