Assertion: Paleobiology is that branch which deals with the study of fossil organisms.
Reason: Paleobotany and paleozoology are the branches of paleobiology.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the question, we will analyze both the assertion and the reason provided, and determine their validity.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Paleobiology is that branch which deals with the study of fossil organisms."
- Paleobiology indeed refers to the study of ancient life through the examination of fossils. This statement is true.

2. **Understanding the Reason**:
- The reason states that "Paleobotany and paleozoology are the branches of paleobiology."
- Paleobotany is the study of fossil plants, and paleozoology is the study of fossil animals. Both of these fields fall under the broader category of paleobiology. This statement is also true.

3. **Evaluating the Relationship**:
- While both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion.
- The assertion defines paleobiology, while the reason provides examples of its branches. However, the reason does not explain why paleobiology is defined as the study of fossil organisms; it merely lists its subdivisions.

4. **Conclusion**:
- Since both statements are true, but the reason does not adequately explain the assertion, we conclude that the assertion is true, the reason is true, but the reason is not the correct explanation of the assertion.

### Final Answer:
- The correct evaluation is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.