Final answer:
Clomipramine (Option B) is the most serotonin-selective tricyclic antidepressant, having mechanisms of action similar to SSRIs, with high selectivity for the serotonin transporter, which increases serotonin levels in the central nervous system.
Step-by-step explanation:
The most serotonin-selective of the tricyclic antidepressants listed is Clomipramine (Option B). Tricyclic antidepressants are an older class of drugs that are used to treat major depression but have been largely replaced by SSRIs due to their side effect profile. Clomipramine is unique among tricyclics because it has a stronger selectivity for the serotonin transporter, similar to the action of SSRIs. SSRIs like Prozac work by blocking the reuptake of serotonin, which increases levels of serotonin in the central nervous system. This mechanism is also how Clomipramine works to exhibit its effects. Unlike most tricyclics, which affect multiple neurotransmitters, Clomipramine is the most serotonin-selective, making it closer in action to SSRIs and beneficial in the treatment of obsessive-compulsive disorders in addition to depression.