Assertion :- Cortisol therapy is useful in organ transplantation
Reason:- Cortisol act as immunosuppresent

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "Cortisol therapy is useful in organ transplantation." This is true because cortisol, a corticosteroid, is often used in medical settings to help prevent the rejection of transplanted organs.

**Hint:** Consider the role of cortisol in the context of organ transplantation.

### Step 2: Understand the Reason
The reason states that "Cortisol acts as an immunosuppressant." This is also true. Cortisol suppresses the immune response, which is crucial in preventing the body from rejecting a transplanted organ.

**Hint:** Think about how the immune system reacts to foreign tissues and how immunosuppressants can help.

### Step 3: Analyze the Relationship
Now we need to determine if the reason correctly explains the assertion. Since cortisol acts as an immunosuppressant and this action is what makes it useful in organ transplantation, the reason does indeed provide a correct explanation for the assertion.

**Hint:** Reflect on how the mechanism of action of cortisol relates to its therapeutic use in transplantation.

### Step 4: Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

**Final Answer:** The correct option is that both assertion and reason are true, and reason is the correct explanation of assertion.