In a Cell with β-Adrenergic Receptors Coupled to the CAMP

In a cell with β-adrenergic receptors coupled to the cAMP second messenger system, what would happen to that signaling pathway if you blocked phosphodiesterases?

A) This would make β-adrenergic receptor activation of adenylate cylase irreversible.
B) This would make β-adrenergic receptor activation using the cAMP pathway last longer.
C) This would have no effects on β-adrenergic receptor signaling using the cAMP pathway.
D) This would prevent β-adrenergic receptor activation from causing any effects through the cAMP pathway.
E) This would mimic the signaling pathway, causing the same effect as activation of the β-adrenergic receptor.