$ That branch of science which deals with the study of Fungi is called Phycology.
! Parasitic fungi cause diseases only in plants.

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 need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "the branch of science which deals with the study of Fungi is called Phycology."
- We need to identify if this statement is true or false.

2. **Correcting the Assertion**:
- The correct term for the study of fungi is "Mycology," not "Phycology."
- Phycology is actually the study of algae. Therefore, the assertion is **false**.

3. **Understanding the Reason**:
- The reason states that "Parasitic fungi cause diseases only in plants."
- We need to evaluate the accuracy of this statement.

4. **Correcting the Reason**:
- Parasitic fungi can cause diseases not only in plants but also in animals and humans.
- For example, many skin diseases in humans are caused by fungal infections. Thus, the reason is also **false**.

5. **Conclusion**:
- Since both the assertion and the reason are incorrect, we conclude that the answer to the question is that both statements are false.

### Final Answer:
Both the assertion and the reason are incorrect.

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