**Core Concept**
The question is about Norepinephrine Reuptake Inhibitors (NRIs), also known as Norepinephrine-Dopamine Reuptake Inhibitors (NDRI). This class of medications works by blocking the reuptake of norepinephrine and dopamine in the brain, thereby increasing the levels of these neurotransmitters. This action is primarily used to treat attention deficit hyperactivity disorder (ADHD) and is also used in the management of depression.

**Why the Correct Answer is Right**
NDRI medications increase the levels of norepinephrine and dopamine in the synaptic cleft by preventing their reuptake. This leads to increased activation of postsynaptic receptors, particularly the alpha-2 adrenergic receptors and the D2 dopamine receptors. The increased activity of these receptors enhances alertness, attention, and motivation, making NDRI medications effective in treating ADHD. The primary mechanism of action of NDRI medications is through the inhibition of the norepinephrine transporter (NET) and the dopamine transporter (DAT).

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is not related to the mechanism of action of NDRI medications.
* **Option B:** This option is incorrect because it describes the mechanism of action of selective serotonin reuptake inhibitors (SSRIs), not NDRI medications.
* **Option C:** This option is incorrect because it describes the mechanism of action of tricyclic antidepressants (TCAs), not NDRI medications.

**Clinical Pearl / High-Yield Fact**
NDRI medications are often used in combination with other medications, such as SSRIs, to enhance their efficacy in treating depression and ADHD.

**Correct Answer:** C.