Assertion : Compressibility factor for ideal gas is one.
Reason : For an ideal gas `PV = nRT` equation is obeyed.

Options

A. If both assertion and reason are correct and reason is correct explanation for assertion
B. If both assertion and reason are correct and reason is not correct explanation for assertion
C. If assertion is correct but reason is incorrect
D. If assertion and reason are both incorreect.

Explanation

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the compressibility factor (Z) for an ideal gas is 1.
- The compressibility factor is defined as \( Z = \frac{PV}{nRT} \). For an ideal gas, this value is indeed equal to 1, which means that the gas behaves ideally under all conditions.

2. **Understanding the Reason**:
- The reason states that for an ideal gas, the equation \( PV = nRT \) is obeyed.
- This is a fundamental equation of state for ideal gases, confirming that the product of pressure (P) and volume (V) equals the number of moles (n) times the ideal gas constant (R) times the temperature (T) in Kelvin.

3. **Evaluating the Truth of the Statements**:
- Both the assertion and the reason are correct statements.
- The assertion correctly identifies that the compressibility factor for an ideal gas is 1.
- The reason correctly explains that the ideal gas law \( PV = nRT \) holds true for ideal gases, which leads to the conclusion that \( Z = 1 \).

4. **Determining the Relationship**:
- Since the reason provides a correct explanation for the assertion, we conclude that both the assertion and the reason are correct, and the reason is indeed the correct explanation for the assertion.

5. **Final Answer**:
- Therefore, the answer to the question is option A: Both assertion and reason are correct, and the reason is the correct explanation for the assertion.