**Core Concept**
The management of depression involves various classes of medications, each targeting different neurotransmitter systems. The efficacy of these medications depends on their ability to modulate these systems, leading to improved mood and reduced symptoms.

**Why the Correct Answer is Right**
The correct answer is **B. Mirtazapine**, as it is a tetracyclic antidepressant that primarily acts as an antagonist at the central presynaptic α2-adrenergic inhibitory autoreceptors and heteroreceptors, increasing the release of norepinephrine and serotonin. However, its efficacy is slightly lower compared to other classes of antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs).

**Why Each Wrong Option is Incorrect**
* **Option A:** SSRIs, like fluoxetine, are generally effective in treating depression, as they increase the levels of serotonin in the synaptic cleft by inhibiting its reuptake. This mechanism is well-established and widely recognized.
* **Option C:** Bupropion is a norepinephrine-dopamine reuptake inhibitor (NDRI) that is effective in treating depression, particularly in patients with a history of smoking or those who have not responded to other antidepressants. Its unique mechanism of action makes it a valuable option.

**Clinical Pearl / High-Yield Fact**
When choosing an antidepressant, it's essential to consider the patient's medical history, potential side effects, and any drug interactions. For example, SSRIs are generally safer in patients with cardiovascular disease, whereas bupropion can increase the risk of seizures, particularly at high doses.

**Correct Answer:** B. Mirtazapine