Which of the following antibiotics was discovered first?

Options

A. Streptomycin
B. Neomycin
C. Erythromycin
D. Penicillin

Answer

To determine which antibiotic was discovered first among the options provided (streptomycin, nemomycin, erythromycin, and penicillin), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Antibiotics**: The antibiotics in question are:
- Streptomycin
- Nemomycin
- Erythromycin
- Penicillin

2. **Research the Discovery Dates**:
- **Penicillin**: Discovered in 1928 by Alexander Fleming. It is widely recognized as the first true antibiotic.
- **Streptomycin**: Discovered in 1943 by Selman Waksman.
- **Erythromycin**: Discovered in 1952 by Eli Lilly and Company.
- **Nemomycin**: This antibiotic is less commonly referenced, and its discovery is not as well-documented as the others, but it is known to have been discovered after penicillin.

3. **Compare the Discovery Dates**:
- Penicillin (1928)
- Streptomycin (1943)
- Erythromycin (1952)
- Nemomycin (after 1928)

4. **Conclusion**: Since penicillin was discovered first in 1928, it is the earliest antibiotic among the options listed.

### Final Answer:
The antibiotic that was discovered first is **Penicillin**.

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