Which of the following microbiologists won, the Nobel Prize in physiology and medicine in 1952 ?

Options

A. Paul Ehrlich
B. Selman A. Waksman
C. Emil A. von Behring
D. Sir Alexander Fleming

Answer

To answer the question of which microbiologist won the Nobel Prize in Physiology and Medicine in 1952, we will analyze each option provided:

1. **Paul Ehrlich**:
- Paul Ehrlich was awarded the Nobel Prize in 1908 for his work in immunology, specifically for his contributions to the field of immunity. Since the question asks for the year 1952, this option is incorrect.

2. **Selman Waksman**:
- Selman Waksman won the Nobel Prize in 1952 for his discovery of streptomycin, the first antibiotic used to treat tuberculosis. This aligns with the year mentioned in the question, making this option correct.

3. **Emil von Behring**:
- Emil von Behring received the Nobel Prize in 1901 for his discovery of the diphtheria antitoxin. Since he was awarded the prize much earlier than 1952, this option is also incorrect.

4. **Sir Alexander Fleming**:
- Sir Alexander Fleming was awarded the Nobel Prize in 1945 for his discovery of penicillin, another significant antibiotic. As this was before 1952, this option is incorrect as well.

After analyzing all the options, we conclude that the correct answer is **Selman Waksman**, who won the Nobel Prize in Physiology and Medicine in 1952.

### Summary of the Solution:
- Paul Ehrlich: Nobel Prize in 1908 (incorrect).
- Selman Waksman: Nobel Prize in 1952 (correct).
- Emil von Behring: Nobel Prize in 1901 (incorrect).
- Sir Alexander Fleming: Nobel Prize in 1945 (incorrect).

**Correct Answer: Selman Waksman (Option B)**