During fixation of one molecule of `CO_(2)` by `C_(3)` plants, number of ATP and NADPH_(2)` required are

Options

A. 3ATP and 2`NADPH_(2)`
B. 5ATP and `NADPH_(2)`
C. 12 ATP and `12 NADPH_(2)`
D. 2ATP and 3 `NADPH_(2)`

Explanation

To determine the number of ATP and NADPH2 required for the fixation of one molecule of CO2 by C3 plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Calvin Cycle**: The fixation of CO2 in C3 plants occurs during the Calvin cycle, which is also known as the C3 cycle. This cycle involves several steps where ATP and NADPH2 are utilized.

2. **Identify the Inputs for CO2 Fixation**: For the fixation of one molecule of CO2, we need to consider the specific reactions that occur in the Calvin cycle.

3. **ATP Requirement**:
- During the Calvin cycle, 3 ATP molecules are required for the conversion of 3-phosphoglycerate (3-PGA) to 1,3-diphosphoglycerate (1,3-BPG).
- Additionally, 1 ATP molecule is used to regenerate ribulose-1,5-bisphosphate (RuBP) from ribulose-5-phosphate, but since we are fixing only one CO2 molecule, we focus on the ATP used in the conversion of 3-PGA.

4. **NADPH2 Requirement**:
- For the reduction of 1,3-diphosphoglycerate to glyceraldehyde-3-phosphate (G3P), 2 NADPH2 molecules are required.

5. **Total Calculation**:
- Therefore, for the fixation of one molecule of CO2, the total requirement is 3 ATP and 2 NADPH2.

6. **Conclusion**: Based on the analysis, the correct answer is that during the fixation of one molecule of CO2 by C3 plants, **3 ATP and 2 NADPH2 are required**.

### Final Answer:
The answer is **3 ATP and 2 NADPH2**.

---