For NADPH + `H^(+)` formation

Options

A. only PS I is required
B. only PS II is required
C. both PS I and PS II are required
D. only stroma is required.

Explanation

To answer the question regarding the formation of NADPH and H⁺, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding Photophosphorylation**:
- Photophosphorylation is the process by which ATP is formed using light energy. It occurs during photosynthesis in plants.

2. **Types of Photophosphorylation**:
- There are two types of photophosphorylation: cyclic and non-cyclic.
- **Cyclic Photophosphorylation**: Involves only Photosystem I (PSI) and primarily produces ATP.
- **Non-Cyclic Photophosphorylation**: Involves both Photosystem I (PSI) and Photosystem II (PSII) and produces both ATP and NADPH.

3. **Formation of NADPH and H⁺**:
- The question specifically asks about the formation of NADPH and H⁺. This occurs during non-cyclic photophosphorylation, where both PS I and PS II are involved.
- During this process, electrons are transferred through a series of proteins, leading to the reduction of NADP⁺ to NADPH and the release of protons (H⁺).

4. **Conclusion**:
- Since the formation of NADPH and H⁺ requires both PS I and PS II, the correct answer to the question is that both PS I and PS II are required.

### Final Answer:
- The correct option is **both PS1 and PS2 are required**.

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