Which of the following is meaningful?

Options

A. Vector/Vector
B. vector
C. Scalar + vector
D. vector / scalar

Answer

To determine which of the following expressions involving vectors and scalars is meaningful, we need to analyze the options based on the rules of vector algebra.

### Step-by-Step Solution:

1. **Understanding Vectors and Scalars**:
- Vectors are quantities that have both magnitude and direction (e.g., force, velocity).
- Scalars are quantities that have only magnitude (e.g., mass, temperature).

2. **Analyzing the Options**:
- **Option 1: Vector + Vector**: This is meaningful because the sum of two vectors results in another vector.
- **Option 2: Scalar + Scalar**: This is also meaningful because the sum of two scalars results in another scalar.
- **Option 3: Vector + Scalar**: This does not make sense because you cannot add a vector and a scalar directly.
- **Option 4: Vector / Scalar**: This is meaningful because dividing a vector by a scalar results in a vector. For example, if we take pressure, which is defined as force (a vector) divided by area (a scalar), this operation is valid.

3. **Conclusion**:
- The only meaningful operation among the given options is **Option 4: Vector / Scalar**.

### Final Answer:
The correct option is **Option 4: Vector / Scalar**.