**Core Concept**
Tetanus is a bacterial infection caused by Clostridium tetani, characterized by muscle rigidity, spasms, and autonomic dysfunction. The infection leads to the release of tetanospasmin, a neurotoxin that inhibits the release of neurotransmitters, resulting in muscle stiffness and spasms.

**Why the Correct Answer is Right**
The patient's symptoms of sweating, hypothermia, and bradycardia (pulse rate <50/min) are consistent with tetanus infection. The diagnosis is further supported by the patient's occupation as a farmer, which increases the risk of tetanus infection due to exposure to contaminated soil. Atropine is the correct treatment for this patient because it counteracts the autonomic dysfunction caused by tetanus, particularly the bradycardia and hypothermia. **Why Each Wrong Option is Incorrect** **Option A:** Ativan (lorazepam) is a benzodiazepine that may be used to manage muscle spasms in tetanus, but it is not the first-line treatment for bradycardia and hypothermia. **Option B:** Naloxone is an opioid antagonist that is used to reverse opioid overdose, and it is not indicated in the treatment of tetanus. **Option C:** Activated charcoal is used to treat poisoning, but it is not effective in treating tetanus infection. **Clinical Pearl / High-Yield Fact** Tetanus infection is often referred to as "lockjaw" due to the characteristic jaw spasms that occur in affected patients. **Correct Answer: D. Atropine**