<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 57-year-old male presents with a primary complaint of erectile dysfunction. After proper evaluation, the patient is started on daily administration of sildenafil. This medication directly causes accumulation of which of the following intracellular mediators?? A: Ca2, B: cGMP, C: AMP, D: NO, E: ANP,  <response>: This is a question about the mechanism of action of sildenafil Viagra in treating erectile dysfunction. Sildenafil is a phosphodiesterase type 5 PDE5 inhibitor that prevents the breakdown of cyclic guanosine monophosphate cGMP. cGMP is an intracellular second messenger that causes smooth muscle relaxation in the corpus cavernosum of the penis, leading to erection. Therefore, sildenafil causes an accumulation of cGMP inside cells.B: cGMP 