Assertion : Intra-uterine devices (IUDs) are very effective contraceptive method.
Reason : IUDs do not allow sperms to enter uterus.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reasons is not the correct expalanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4).

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Intra-uterine devices (IUDs) are a very effective contraceptive method."
- This is true. IUDs are widely recognized and used as effective methods of contraception. They can prevent pregnancy for several years depending on the type.

**Hint**: Consider the effectiveness of different contraceptive methods and the role of IUDs in preventing pregnancy.

2. **Understanding the Reason**:
- The reason provided is that "IUDs do not allow sperms to enter the uterus."
- This statement is false. IUDs do not function as a physical barrier like condoms. Instead, they create an environment in the uterus that is hostile to sperm and prevents fertilization.

**Hint**: Think about how IUDs work compared to other contraceptive methods that act as barriers.

3. **Analyzing the Relationship**:
- The assertion is true, but the reason is false. Therefore, the two statements are not logically connected. The effectiveness of IUDs does not solely depend on preventing sperm from entering the uterus.

**Hint**: Evaluate whether the reason provided supports the assertion or if it contradicts it.

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

**Hint**: Identify the correct option based on the truth values of the assertion and reason.

### Final Answer:
The correct answer is that the assertion is true, and the reason is false.