Assertion : It is important that the organisms should have cell.
Reason : A cell keeps its chemical composition steady within its boundary.

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason if false
D. If both the assertion and reason are false

Explanation

To analyze the given assertion and reason, we can break it down into a step-by-step solution.

### Step 1: Understand the Assertion
The assertion states that "It is important that organisms should have cells." This implies that cells are fundamental units of life and are necessary for the existence of organisms.

### Step 2: Understand the Reason
The reason given is "A cell keeps its chemical composition steady within its boundary." This means that cells maintain a stable internal environment (homeostasis) despite changes in the external environment.

### Step 3: Connect the Assertion and Reason
The assertion and reason are connected because the stability of the internal environment provided by cells is crucial for the overall functioning of an organism. Cells are responsible for maintaining this steady state, which is essential for life.

### Step 4: Evaluate the Truth of Both Statements
Both the assertion and the reason are true:
- Cells are indeed essential for all living organisms.
- Cells maintain a stable internal environment, which is vital for the survival and proper functioning of the organism.

### Step 5: Determine the Relationship
Since the reason explains why the assertion is true, we conclude that the reason is a correct explanation of the assertion.

### Final Conclusion
Both the assertion and reason are true, 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.