**Core Concept**
Sympathetic stimulation on the bronchus causes a contraction of the bronchial smooth muscle, leading to bronchoconstriction, which is an opposite effect of parasympathetic stimulation. This response is mediated by the sympathetic nervous system's release of neurotransmitters such as norepinephrine.

**Why the Correct Answer is Right**
The contraction of bronchial smooth muscle in response to sympathetic stimulation is due to the activation of alpha-1 adrenergic receptors (α1-adrenoceptors) on the smooth muscle cells. These receptors, when stimulated by norepinephrine, initiate a signaling cascade that results in muscle contraction and bronchoconstriction. The parasympathetic nervous system, on the other hand, causes bronchodilation by releasing acetylcholine, which acts on muscarinic receptors to relax the bronchial smooth muscle.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because sympathetic stimulation on the bronchus causes contraction, not relaxation of bronchial smooth muscle.
**Option B:** Incorrect as there is no direct relationship between sympathetic stimulation on the bronchus and increased mucus production.
**Option C:** Incorrect as sympathetic stimulation does not lead to bronchodilation; it causes bronchoconstriction.

**Clinical Pearl / High-Yield Fact**
In clinical scenarios, the use of bronchodilators, such as beta-2 agonists, is often employed to counteract the effects of sympathetic stimulation on the bronchus and relieve bronchoconstriction in conditions such as asthma or chronic obstructive pulmonary disease (COPD).

**Correct Answer:** C.