The `C_(4)` plants are photosynthesis more efficient then `C_(3)` plant because
(a) The `CO_(2)` efflux is not prevented
(b) They have more chloroplasts
(c) The `CO_(2)` compensation point is more.
(d) `CO_(2)` generated during photorespiration is trapped and recycled through PEP carboxylase

Options

A. The `CO_(2)` efflux is not prevented
B. They have more chloroplasts
C. The `CO_(2)` compensation point is more.
D. `CO_(2)` generated during photorespiration is trapped and recycled through PEP carboxylase

Answer

To determine why C4 plants are more efficient in photosynthesis than C3 plants, we need to analyze the options provided:

1. **Understanding C4 and C3 Plants**:
- C3 plants primarily use the Calvin cycle for photosynthesis and have a single type of cell containing chloroplasts (mesophyll cells).
- C4 plants have a specialized anatomy known as Kranz anatomy, which includes two types of cells: mesophyll cells and bundle sheath cells. This structure allows for a more efficient process of capturing and utilizing CO2.

2. **Analyzing the Options**:
- **(a) The CO2 efflux is not prevented**: This statement is not correct because C4 plants are designed to minimize CO2 loss.
- **(b) They have more chloroplasts**: While C4 plants do have chloroplasts in both mesophyll and bundle sheath cells, this is not the primary reason for their efficiency.
- **(c) The CO2 compensation point is more**: This statement is misleading; C4 plants have a lower CO2 compensation point, allowing them to photosynthesize efficiently even at low CO2 levels.
- **(d) CO2 generated during photorespiration is trapped and recycled through PEP carboxylase**: This is the correct option. C4 plants can effectively capture and utilize CO2 that is released during photorespiration, thus enhancing their efficiency.

3. **Conclusion**:
- The most accurate reason why C4 plants are more efficient in photosynthesis than C3 plants is option **(d)**: "CO2 generated during photorespiration is trapped and recycled through PEP carboxylase."

### Step-by-Step Solution:
1. **Identify the types of plants**: Understand the difference between C3 and C4 plants.
2. **Examine the options**: Analyze each option to see if it correctly explains the efficiency of C4 plants.
3. **Select the correct answer**: Determine that option (d) is the correct explanation for the increased efficiency of C4 plants.