Assertion : Liqefaction of `H_(2)` and `He` are very difficult.
Reason : Critical temperature of `H_(2)` and `He` gases are high.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Explanation

To analyze the assertion and reason provided in the question, we will break down the concepts of liquefaction, critical temperature, and the specific cases of hydrogen (H₂) and helium (He).

### Step-by-Step Solution:

1. **Understanding Liquefaction**:
- Liquefaction is the process of converting a gas into a liquid state. This typically requires the application of pressure and/or a decrease in temperature.

2. **Assertion Analysis**:
- The assertion states that the liquefaction of hydrogen (H₂) and helium (He) is very difficult. This is true because both gases require very low temperatures to liquefy.

3. **Understanding Critical Temperature**:
- Critical temperature (Tc) is the temperature above which a gas cannot be liquefied, regardless of the pressure applied. For a gas to be liquefied, it must be cooled below its critical temperature.

4. **Reason Analysis**:
- The reason states that the critical temperatures of H₂ and He are high. However, this is incorrect. The critical temperatures of these gases are actually very low:
- The critical temperature of hydrogen (H₂) is approximately 33 K (-240 °C).
- The critical temperature of helium (He) is about 6 K (-267 °C).

5. **Conclusion**:
- Since the assertion is true (liquefaction of H₂ and He is difficult) but the reason is false (the critical temperatures are low, not high), we conclude that the assertion is correct but the reason is incorrect.

### Final Answer:
- The assertion is true, while the reason is false.