$ Protoplasm is the physical basis of a cell.
! Angstrom is a unit of measurements of electron microscopy.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

**Step-by-Step Solution:**

1. **Understanding Protoplasm:**
- Protoplasm is often referred to as the physical basis of a cell. It is a complex substance that contains all the essential components necessary for life processes.
- Protoplasm is present within the cell and is responsible for various cellular functions, including metabolism, growth, and reproduction.

2. **Defining Protoplasm:**
- Protoplasm can be described as a crystallocolloidal complex, which means it has properties of both a solid and a liquid. This unique structure allows it to support various biochemical reactions essential for life.

3. **Analyzing the Statement about Protoplasm:**
- The statement "Protoplasm is the physical basis of a cell" is true because it encompasses all the life processes and is the medium in which cellular activities occur.

4. **Understanding Angstrom:**
- An angstrom (Å) is a unit of measurement that is commonly used in fields such as physics, chemistry, and crystallography. It is equal to \(10^{-10}\) meters.
- This unit is particularly useful for measuring very small distances, such as atomic and molecular dimensions.

5. **Analyzing the Statement about Angstrom:**
- The statement "Angstrom is a unit of measurement of electron microscopy" is also true. Angstroms are used to measure wavelengths of electrons and the dimensions of structures observed in electron microscopy.

6. **Conclusion:**
- Both statements are correct. However, they are independent of each other and do not serve as explanations for one another. Therefore, the conclusion is that both statements are true, but they are not related in terms of causation.