**Core Concept**
The question is testing knowledge of monoamine oxidase inhibitors (MAOIs), a class of medications used to treat depression and Parkinson's disease. Specifically, we're looking at the selective inhibition of monoamine oxidase B (MAO-B), an enzyme involved in the breakdown of dopamine.

**Why the Correct Answer is Right**
Selective MAO-B inhibitors target the MAO-B enzyme, which is predominantly found in the brain and is responsible for the breakdown of dopamine. By inhibiting this enzyme, these medications increase the levels of dopamine in the brain, providing therapeutic benefits in conditions such as Parkinson's disease. Selegiline (Eltanil) is a classic example of a selective MAO-B inhibitor.

**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because **tranylcypromine** is a non-selective MAOI, inhibiting both MAO-A and MAO-B enzymes, which can lead to increased levels of catecholamines and serotonin, as well as tyramine, a potent pressor agent.
**Option B:** is incorrect because **rasagiline** is a selective MAO-B inhibitor, but it's not as commonly used as selegiline.
**Option C:** is incorrect because **moclobemide** is a reversible inhibitor of MAO-A, not MAO-B.

**Clinical Pearl / High-Yield Fact**
Selegiline has a unique property called "suicide inhibition," where it irreversibly inhibits MAO-B at low doses and is reversible at higher doses, allowing for a safer profile.

**Correct Answer:** B. Rasagiline