In `C_(4)` plants, the carbon dioxide occurs in

Options

A. guard cells
B. spongy cells
C. palisade tissue
D. bundle sheath cells

Answer

To answer the question "In C4 plants, the carbon dioxide occurs in", we need to analyze the options provided and understand the specific characteristics of C4 plants.

### Step-by-Step Solution:

1. **Understand C4 Plants**: C4 plants utilize a unique photosynthetic pathway known as the C4 cycle, which is primarily found in certain monocots. This pathway allows them to efficiently fix carbon dioxide even in conditions of low CO2 concentration.

2. **Evaluate Each Option**:
- **Option 1: Guard Cell**: Guard cells are responsible for the opening and closing of stomata, which regulate gas exchange. They do not directly participate in the fixation of carbon dioxide. Therefore, this option is incorrect.

- **Option 2: Spongy Cell**: Spongy mesophyll cells primarily facilitate gas exchange and provide space for air within the leaf. While they play a role in photosynthesis, they are not the primary site for carbon dioxide fixation in C4 plants. Thus, this option is also incorrect.

- **Option 3: Palisade Tissue**: Palisade mesophyll cells are found in dicot plants and are involved in photosynthesis. However, in C4 plants, the primary fixation of carbon dioxide occurs in a different type of cell. Therefore, this option is incorrect as well.

- **Option 4: Bundle Sheath Cell**: In C4 plants, the carbon dioxide is primarily fixed in the mesophyll cells, where it combines with phosphoenolpyruvate to form oxaloacetic acid, a four-carbon compound. This compound is then transported to the bundle sheath cells, where it is converted back into a three-carbon compound (pyruvate) and CO2 is released for the Calvin cycle. Therefore, this option is correct.

3. **Conclusion**: The correct answer is that in C4 plants, carbon dioxide occurs in the **bundle sheath cells**.

### Final Answer:
In C4 plants, carbon dioxide occurs in **bundle sheath cells**.