The question pertains to identifying the correct term for a professional who cares for sick animals. Let's analyze each option:
- Pharmacist: A pharmacist is a professional who prepares and dispenses medications for humans, not animals.
- Zoologist: A zoologist studies animal biology, ecosystems, and behavior, but does not typically treat sick animals.
- Veterinarian: A veterinarian is a medical professional who diagnoses, treats, and helps prevent diseases and injuries in animals.
- Surgeon: A surgeon performs surgical operations, typically as a specialization in human medical practices. However, veterinary surgeons operate specifically on animals.
Given these explanations, the correct answer is Veterinarian as they are trained to treat sick animals.