In the leaves of `C_(4)` plants, malic acid formation during `CO_(2)` fixation occurs in the cells of
(a) Epidermis
(b) Mesophyll
(c) Bundle sheath
(d) Phloem

Options

A. Epidermis
B. Mesophyll
C. Bundle sheath
D. Phloem

Answer

To solve the question regarding where malic acid formation occurs during CO₂ fixation in C₄ plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand C₄ Photosynthesis**: C₄ plants have a specialized mechanism for photosynthesis that involves two types of cells: mesophyll cells and bundle sheath cells. This is known as Kranz anatomy.

2. **Identify the Role of Mesophyll Cells**: In C₄ plants, when CO₂ is taken up, it first enters the mesophyll cells. Here, it combines with phosphoenolpyruvate (PEP) to form oxaloacetic acid (OAA) in the presence of the enzyme PEP carboxylase.

3. **Conversion to Malic Acid**: The oxaloacetic acid (a four-carbon compound) is then converted into malic acid, which is also a four-carbon compound. This conversion occurs within the mesophyll cells.

4. **Transport to Bundle Sheath Cells**: After malic acid is formed, it is transported to the bundle sheath cells, where it undergoes decarboxylation to release CO₂, which then enters the Calvin cycle.

5. **Conclusion**: Since the formation of malic acid occurs in the mesophyll cells, the correct answer to the question is option (b) Mesophyll.

### Final Answer:
(b) Mesophyll