**Core Concept**
Wernicke's aphasia is a type of fluent aphasia characterized by the inability to understand spoken language, with intact spontaneous speech. It results from damage to a critical area in the brain responsible for language comprehension.

**Why the Correct Answer is Right**
Wernicke's aphasia is caused by a lesion in the posterior superior temporal gyrus, specifically in the area known as Wernicke's area. This region is crucial for language comprehension and is located in the left hemisphere of the brain in most right-handed individuals. The damage to Wernicke's area disrupts the ability to understand spoken language, leading to the characteristic symptoms of Wernicke's aphasia, such as neologisms, paraphasias, and a lack of attention to the conversation.

**Why Each Wrong Option is Incorrect**
**Option A:** The precentral gyrus is primarily responsible for motor function and is the location of the primary motor cortex, which controls voluntary movements. Damage to this area would result in motor deficits, not language disorders.
**Option B:** The inferior frontal gyrus, particularly Broca's area, is involved in speech production and articulation, not language comprehension. Lesions in this area would result in Broca's aphasia, characterized by non-fluent speech.
**Option D:** The inferior temporal gyrus is involved in visual processing and object recognition, not language comprehension. Damage to this area would result in visual field defects or object recognition disorders, not language disorders.

**Clinical Pearl / High-Yield Fact**
Wernicke's aphasia is often associated with posterior cerebral artery (PCA) infarcts, particularly in the territory of the temporo-parietal branch of the PCA. Recognizing the relationship between Wernicke's aphasia and PCA infarcts can help in localizing the lesion and guiding further management.

**✓ Correct Answer: C. Superior temporal gyrus**