Hydrogen satisfies the conditions of an ideal fuel but cannot be used freely because
(i) it has high calorific value.
(ii) it is difficult to store and transport.
(iii) it is soluble in water.
(iv) it is highly inflammable.
Select the correct statements.

Options

A. (i) and (iii)
B. (i) and (ii)
C. (ii) and (iv)
D. (iii) and (iv)

Explanation

To determine why hydrogen cannot be used freely as a fuel despite satisfying the conditions of an ideal fuel, we will analyze each of the given statements one by one.

### Step-by-Step Solution:

1. **Understanding High Calorific Value**:
- Hydrogen does have a high calorific value, which means it can produce a large amount of energy when burned. However, having a high calorific value is not a reason for not using it freely. In fact, it is a desirable trait in fuels.
- **Conclusion**: Statement (i) is incorrect.

2. **Difficulty in Storage and Transport**:
- Hydrogen is indeed difficult to store and transport due to its low density and the fact that it is a gas at room temperature. This makes it challenging to contain in tanks or pipelines without special materials and conditions.
- **Conclusion**: Statement (ii) is correct.

3. **Solubility in Water**:
- Hydrogen is only sparingly soluble in water, meaning it does not dissolve well. This characteristic does not significantly hinder its use as a fuel.
- **Conclusion**: Statement (iii) is incorrect.

4. **Highly Inflammable**:
- Hydrogen is highly inflammable, meaning it can catch fire easily and burn rapidly. This poses safety risks, making it less practical for widespread use without proper precautions.
- **Conclusion**: Statement (iv) is correct.

### Final Conclusion:
Based on the analysis:
- The correct statements regarding why hydrogen cannot be used freely are (ii) it is difficult to store and transport, and (iv) it is highly inflammable.

Therefore, the correct answer is: **Statements (ii) and (iv) are correct.**