**Core Concept**
Baroreceptors are specialized mechanoreceptors located in the walls of the carotid sinus and aortic arch that detect changes in arterial blood pressure. When activated, they trigger a reflex response to maintain blood pressure homeostasis.

**Why the Correct Answer is Right**
Baroreceptor stimulation leads to the activation of the baroreflex arc, which involves the afferent stimulation of baroreceptors, followed by the efferent stimulation of the vagus nerve and the subsequent inhibition of the sympathetic nervous system and stimulation of the parasympathetic nervous system. This results in a decrease in heart rate and a decrease in cardiac output, thereby reducing blood pressure. The decrease in sympathetic tone also leads to vasodilation, further contributing to the reduction in blood pressure.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the effect of baroreceptor stimulation on the cardiovascular system.
**Option B:** This option is incorrect because baroreceptor stimulation does not lead to an increase in blood pressure; rather, it results in a decrease in blood pressure.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that baroreceptor stimulation is a critical mechanism for maintaining blood pressure homeostasis, and its dysfunction can lead to conditions such as hypertension and orthostatic hypotension.

**Correct Answer:** B. Decrease in blood pressure.