Assertion (A): Toxoids are used in vaccines.
Reason (R): Toxoids are bacterial toxins which help in the formation of antibodies.

Options

A. Both A and R are true and R is the correct explanation for A.
B. Both A and R are true, but R is not the correct explanation for A.
C. A is true and 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 "Toxoids are used in vaccines." To evaluate this, we need to know what toxoids are. Toxoids are inactivated toxic compounds produced by certain bacteria. They are used in vaccines to help the body develop immunity without causing disease.

2. **Understanding the Reason (R)**: The reason provided is that "Toxoids are bacterial toxins which help in the formation of antibodies." This is also true. Toxoids are indeed derived from bacterial toxins, and they stimulate the immune system to produce antibodies against these toxins.

3. **Linking Assertion and Reason**: Now, we need to determine if the reason correctly explains the assertion. Since toxoids are used in vaccines specifically to provoke an immune response (i.e., the formation of antibodies), the reason does indeed provide a correct explanation for the assertion.

4. **Conclusion**: Both the assertion and the reason are correct, and the reason accurately explains why toxoids are used in vaccines. Therefore, we can conclude that both statements are true and the reason is a correct explanation of the assertion.

**Final Answer**: Both Assertion (A) and Reason (R) are correct, and the reason correctly explains the assertion.

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