A,B and O blood groups were discovered by

Options

A. Landsteiner
B. Weiner
C. Levine
D. Bernstein

Answer

**Step-by-Step Solution:**

1. **Understanding Blood Groups**: The question asks about the discovery of A, B, and O blood groups. These blood groups are part of the ABO blood group system, which classifies human blood based on the presence or absence of specific antigens on the surface of red blood cells (RBCs).

2. **Identifying the Antigens**: The ABO blood group system is determined by the presence of two antigens: Antigen A and Antigen B. Depending on which antigens are present, a person can have one of four blood types: A, B, AB, or O.

3. **Historical Context**: The discovery of these blood groups is attributed to a scientist. The question provides four options: Landsteiner, Wainer, Levin, and Bernstein.

4. **Researching the Scientist**: Among the options, Carl Landsteiner is known for his work in immunology and blood classification. He identified the A and B antigens and established the ABO blood group system.

5. **Conclusion**: Carl Landsteiner is credited with the discovery of the A, B, and O blood groups in the year 1901. Therefore, the correct answer to the question is Carl Landsteiner.

**Final Answer**: The A, B, and O blood groups were discovered by Carl Landsteiner.

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