**Core Concept**
Wernicke's area is a region in the brain responsible for processing language, specifically the comprehension of spoken language. It is named after the German neurologist Carl Wernicke, who first identified this region in the late 19th century. Wernicke's area is located in the posterior part of the superior temporal gyrus in the dominant hemisphere of the brain.

**Why the Correct Answer is Right**
Wernicke's area is essential for understanding spoken language, including syntax, semantics, and phonology. It is connected to Broca's area, which is responsible for speech production, through the arcuate fasciculus. This connection allows for the integration of language comprehension and production. Lesions in Wernicke's area can lead to Wernicke's aphasia, characterized by difficulty understanding spoken language.

**Why Each Wrong Option is Incorrect**
**Option A:** The primary motor cortex is located in the precentral gyrus and is responsible for motor function, not language processing.
**Option B:** The primary sensory cortex is located in the postcentral gyrus and is responsible for processing sensory information, not language comprehension.
**Option C:** The hippocampus is a structure involved in memory formation and spatial navigation, not language processing.

**Clinical Pearl / High-Yield Fact**
Wernicke's area is often damaged in patients with Wernicke's aphasia, which can be caused by stroke, traumatic brain injury, or neurodegenerative diseases such as Alzheimer's disease.

**Correct Answer: C. The posterior part of the superior temporal gyrus.**