NADH is produced in

Options

A. Photosystem II
B. Photosystem I
C. Glycolysis
D. Both A and B

Answer

**Step-by-Step Solution:**

1. **Understanding NADH**: NADH is a coenzyme that plays a crucial role in cellular respiration. It is produced during various metabolic processes and is involved in the transfer of electrons.

2. **Identifying the Processes**: The question asks where NADH is produced. The options given are:
- Photosystem II
- Photosystem I
- Glycolysis
- Both A and B

3. **Analyzing Photosystems**: Photosystem I and Photosystem II are part of the photosynthetic process in plants. They are involved in the light-dependent reactions and primarily produce NADPH, not NADH. Therefore, these options can be eliminated.

4. **Focusing on Glycolysis**: Glycolysis is a metabolic pathway that breaks down glucose to produce energy. During this process, NADH is produced. Glycolysis occurs in the cytoplasm and is the first step in cellular respiration.

5. **Conclusion**: Since NADH is produced during glycolysis and not in the photosystems, the correct answer to the question is that NADH is produced in glycolysis.

**Final Answer**: NADH is produced in glycolysis.

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