Where does dark reaction of photosynthesis take place?

Options

A. Thylakoid lumen
B. Thylakoid membrane
C. Stroma of the chloroplast
D. Matrix of the mitochondria

Answer

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis consists of two main stages: the light reactions and the dark reactions (Calvin cycle). The light reactions occur in the presence of sunlight, while the dark reactions can occur in the absence of light.

2. **Identifying the Location of Light Reactions**: The light reactions take place in the thylakoid membranes of the chloroplasts. This is where chlorophyll is concentrated, and it captures light energy to produce ATP and NADPH.

3. **Identifying the Location of Dark Reactions**: The dark reactions, or Calvin cycle, occur in the stroma of the chloroplasts. The stroma is the fluid-filled space surrounding the thylakoids.

4. **Understanding the Role of the Stroma**: In the stroma, the ATP and NADPH produced during the light reactions are utilized to convert carbon dioxide into glucose through a series of enzymatic reactions.

5. **Conclusion**: Therefore, the dark reactions of photosynthesis take place in the stroma of the chloroplast.

### Final Answer:
The dark reaction of photosynthesis takes place in the **stroma of the chloroplast**.

---