Mitochondria play a very important role in :

Options

A. cellular metabolism
B. regeneration
C. intercellular digestion
D. intracellular digestion

Explanation

### Step-by-Step Solution:

1. **Understanding Mitochondria**: Mitochondria are known as the powerhouse of the cell. They are double membrane-bound organelles found in most eukaryotic cells.

2. **Role in Cellular Metabolism**: The primary function of mitochondria is to facilitate cellular metabolism, particularly through processes that generate energy.

3. **Energy Production**: Mitochondria are crucial for energy production via oxidative phosphorylation, which is part of the electron transport chain. This process converts biochemical energy from nutrients into adenosine triphosphate (ATP), the energy currency of the cell.

4. **Other Functions**: Besides energy metabolism, mitochondria also play roles in controlling the cell's stress response and are involved in various biosynthetic processes.

5. **Evaluating Options**: The question asks about the important roles of mitochondria. The correct answer is that they play a very important role in cellular metabolism, as this encompasses their primary function of energy production.

6. **Conclusion**: Therefore, the answer to the question is that mitochondria play a very important role in cellular metabolism.

### Final Answer:
Mitochondria play a very important role in cellular metabolism.

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