Classify the following into antihistamine, antacid, tranquilliser, antibiotic drug : penicillin, meprobamate, terfenadine, ranitidine.

Explanation

To classify the given drugs into their respective categories, we will analyze each drug based on its primary use and mechanism of action.

### Step-by-Step Solution:

1. **Identify the first drug: Penicillin**
- **Classification**: Antibiotic
- **Reason**: Penicillin is a well-known antibiotic that is used to treat bacterial infections by inhibiting the growth of bacteria.

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