A: Human blood always contains more amount of
`CO_(2)` than blood oxygen.
R: Solubility coefficient of `CO_(2)` is more than `O_(2)`.

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

Answer

To solve the question regarding the assertion and reason about the levels of carbon dioxide (CO₂) and oxygen (O₂) in human blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "human blood always contains more amount of CO₂ than blood oxygen."
- This is a true statement as the concentration of CO₂ in the blood is generally higher than that of O₂.

2. **Understanding the Reason**:
- The reason provided is that "the solubility coefficient of CO₂ is more than O₂."
- This statement is also true. CO₂ is indeed more soluble in blood than O₂.

3. **Connecting the Assertion and Reason**:
- The reason explains why the assertion is true. The higher solubility of CO₂ compared to O₂ means that more CO₂ can be dissolved in the blood, leading to a higher concentration of CO₂ in the blood than O₂.

4. **Conclusion**:
- Both the assertion and the reason are correct, and the reason correctly explains the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.