**Core Concept**
The question tests the student's knowledge of the pharmacological effects of various drugs, specifically those related to the autonomic nervous system. It requires understanding of how different drugs affect blood pressure and heart rate.

**Why the Correct Answer is Right**
The correct answer is related to a drug that, even in overdose, does not typically cause both hypotension and bradycardia. This suggests a drug that might have a different mechanism of action or side effect profile compared to others.

**Why Each Wrong Option is Incorrect**
**Option A:** Would likely cause both hypotension and bradycardia due to its effects on the autonomic nervous system.
**Option B:** Similarly, would be expected to cause these symptoms due to its pharmacological properties.
**Option C:** Is known for its potential to cause hypotension but the bradycardia component can vary based on the specific drug and context.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that the effects of drug overdoses can vary widely, and understanding the specific pharmacodynamics and pharmacokinetics of each drug is key to managing such cases. Recognizing patterns of toxicity can help in diagnosing and treating overdoses effectively.

**Correct Answer:** D. **Atropine**