Assertion: Some essential elements are called structural element of cells
Reason: These essential elements are the components of certain biomolecules.

Options

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

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Assertion**: The assertion states that some essential elements are referred to as structural elements of cells. This implies that these elements play a crucial role in forming the structure of the cells.

2. **Understanding the Reason**: The reason provided is that these essential elements are components of certain biomolecules. This means that these elements are integral parts of larger molecules that make up the structure of cells.

3. **Identifying Essential Elements**: Essential elements for plants include macronutrients (like Carbon, Hydrogen, Oxygen, Nitrogen) and micronutrients. These elements are vital for various biological processes and the overall health of the plant.

4. **Linking Assertion and Reason**: The assertion can be supported by the reason because the structural elements of cells (like proteins, starches, and cellulose) are indeed made up of these essential elements. For example, Carbon, Hydrogen, and Oxygen are fundamental components of carbohydrates and other biomolecules.

5. **Conclusion**: Since the reason explains why certain essential elements are considered structural elements of cells, we can conclude that the reason is a correct explanation for the assertion.

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

---