Assertion (A): Photosynthesis is an anabolic process.
Reason (R): The process of photosynthesis occurs in chlorophyll.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Photosynthesis is an anabolic process."
- An anabolic process is one that involves the synthesis of complex molecules from simpler ones. In photosynthesis, plants convert carbon dioxide and water into glucose, which is a complex carbohydrate.

2. **Analyzing the Reason (R)**:
- The reason given is "The process of photosynthesis occurs in chlorophyll."
- Chlorophyll is a pigment found in plants that absorbs light energy, but photosynthesis itself occurs in the chloroplasts, which contain chlorophyll.

3. **Evaluating the Truth of Each Statement**:
- The assertion (A) is true because photosynthesis is indeed an anabolic process.
- The reason (R) is false because while chlorophyll is involved in the process, photosynthesis occurs in the chloroplasts, not in chlorophyll itself.

4. **Conclusion**:
- Since the assertion is true and the reason is false, the correct relationship is that the assertion is true but the reason is false.

5. **Selecting the Correct Option**:
- Based on the evaluation, the correct option is: "Assertion is true but reason is false."

### Final Answer:
The correct answer is option 3: "Assertion is true but reason is false."

---