Penicillin was discovered by:

Options

A. Robert Brown
B. Robert Hooke
C. Fleming
D. B. McClintock

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who discovered penicillin, which is a well-known antibiotic.

2. **Identifying the Options**: The options provided are:
- A) Robert Brown
- B) Robert Huxley
- C) Alexander Fleming
- D) Barbara McClintock

3. **Recalling Historical Context**: Penicillin was discovered in the early 20th century. It is important to recall who was conducting research during that time related to antibiotics.

4. **Identifying the Correct Scientist**:
- Alexander Fleming is known for his work with bacteria, particularly Staphylococcus.
- He observed that a mold (Penicillium notatum) growing on his culture plates inhibited the growth of the bacteria around it.

5. **Confirming the Discovery**:
- This observation led to the identification of penicillin as the first true antibiotic, which is effective against bacterial infections by inhibiting cell wall synthesis.

6. **Eliminating Incorrect Options**:
- Robert Brown is known for discovering the nucleus.
- Robert Huxley is not associated with the discovery of penicillin.
- Barbara McClintock is known for her work on jumping genes (transposable elements).

7. **Final Answer**: Based on the information gathered, the correct answer is **C) Alexander Fleming**.

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