Which of the Following Is a TRUE Statement

Multiple Choice

Which of the following is a TRUE statement?

A) All protein kinases are activated by cyclic AMP.
B) The subunit of the protein kinase that binds cyclic AMP is the catalytic subunit.
C) Caffeine increases the rate of cyclic AMP degradation.
D) Hormones activate adenylate cyclase by binding directly to the adenylate cyclase molecule.
E) The enzyme that inactivates cyclic AMP is a phosphodiesterase.