**Core Concept**
Baroreceptors located in the carotid sinus and aortic arch detect changes in blood pressure and transmit signals via the glossopharyngeal and vagus nerves to the brainstem. The primary site of integration for these signals is the nucleus of tractus solitarius (NTS), which initiates autonomic reflexes to regulate blood pressure.

**Why the Correct Answer is Right**
The nucleus of tractus solitarius (NTS) is the first central relay for visceral afferent inputs, including those from baroreceptors. It receives direct input from the carotid and aortic baroreceptors via the glossopharyngeal and vagus nerves. The NTS then processes this information and activates descending pathways to modulate sympathetic and parasympathetic outflow, thereby regulating blood pressure through the baroreceptor reflex.

**Why Each Wrong Option is Incorrect**
Option A: The caudal ventrolateral medulla (CVLM) is involved in *output* of the baroreflex, not initial signal reception. It receives input from the NTS but does not receive the original baroreceptor signal.
Option B: The rostral dorsolateral medulla (rDLM) is part of the vasomotor center and regulates sympathetic tone, but it is not the initial site of baroreceptor signal processing.
Option D: This is incorrect because the nucleus of tractus solitarius *is* the correct site of signal reception.

**Clinical Pearl / High-Yield Fact**
The nucleus of tractus solitarius is the *entry point* for all visceral afferent signals, including baroreceptor input. Remember: **"Baroreceptors → Vagus/Glossopharyngeal → NTS → CVLM → Sympathetic/Parasympathetic output"** — the NTS is the starting point.

✓ Correct Answer: C. Nucleus of tractus solitarius