Penicillin is an example of

Options

A. Analgesic
B. Antiseptic
C. Antibiotic
D. Anaesthetic

Answer

To determine what type of drug penicillin is, we can analyze the options provided:

1. **Analgesic**: These are drugs that relieve pain. Common examples include aspirin and ibuprofen. Penicillin does not primarily serve this function.

2. **Antiseptic**: These are substances that prevent the growth of disease-causing microorganisms. Examples include alcohols and chlorhexidine. Penicillin does not fit this category as it is not used to disinfect or clean wounds.

3. **Antibiotic**: This class of drugs is used to treat bacterial infections. Penicillin specifically targets bacteria and is widely recognized as one of the first antibiotics discovered.

4. **Anesthetic**: These drugs induce a temporary loss of sensation or awareness, often used during surgeries. Examples include desflurane. Penicillin does not have this effect.

Based on this analysis, the correct answer is:

**C. Antibiotic**

### Step-by-Step Solution:
1. **Identify the categories of drugs**: Understand the definitions of analgesics, antiseptics, antibiotics, and anesthetics.
2. **Evaluate each option**: Analyze what each category does and compare it with the function of penicillin.
3. **Determine the correct category**: Conclude that penicillin is used to treat bacterial infections, thus classifying it as an antibiotic.