The first carbon dioxide acceptor in `C_(4)`-plants is

Options

A. phosphoenol-pyruvate
B. ribulose 1,5-diphosphate
C. oxalo acetic acid
D. phosphoglyceric acid

Explanation

To determine the first carbon dioxide acceptor in C4 plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding C4 Photosynthesis**:
- C4 plants utilize a different pathway for photosynthesis compared to C3 plants. In C4 photosynthesis, carbon dioxide is initially fixed in a specific manner to enhance efficiency, especially in hot and dry environments.

2. **Identifying the Carbon Dioxide Acceptors**:
- In the C4 pathway, the first step involves the fixation of carbon dioxide. The key to this process is identifying the molecule that first captures carbon dioxide.

3. **Recognizing the Key Molecules**:
- The primary molecules involved in the C4 pathway include:
- Phosphoenolpyruvate (PEP)
- Ribulose 1,5-diphosphate (RuBP)
- Oxaloacetic acid (OAA)
- Phosphoglyceric acid (PGA)

4. **Determining the First Carbon Dioxide Acceptor**:
- In C4 plants, the first carbon dioxide acceptor is phosphoenolpyruvate (PEP). When carbon dioxide is fixed, it combines with PEP to form oxaloacetic acid (OAA).

5. **Conclusion**:
- Therefore, the first carbon dioxide acceptor in C4 plants is **A. Phosphoenolpyruvate**.

### Final Answer:
The first carbon dioxide acceptor in C4 plants is **A. Phosphoenolpyruvate**.

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