Fluids are

Options

A. solids and liquids
B. liquids and gases
C. solids and gases
D. only liquids

Explanation

### Step-by-Step Solution

1. **Understanding the Definition of Fluids**:
- Fluids are substances that can flow easily. This includes both liquids and gases. The key characteristic of fluids is that they do not have a fixed shape; they take the shape of the container they are in.

2. **Identifying Properties of Fluids**:
- Fluids have the ability to flow and their shape is not fixed. This distinguishes them from solids, which have a definite shape and do not flow.

3. **Analyzing the Options**:
- The options provided are:
1. Solids and Liquids
2. Liquids and Gases
3. Solids and Gases
4. Only Liquids

4. **Evaluating Each Option**:
- **Option 1: Solids and Liquids**: This is incorrect because solids do not flow and therefore cannot be classified as fluids.
- **Option 2: Liquids and Gases**: This is correct because both liquids and gases can flow and do not have a fixed shape.
- **Option 3: Solids and Gases**: This is incorrect because, similar to option 1, solids do not flow.
- **Option 4: Only Liquids**: This is also incorrect because gases are included in the definition of fluids.

5. **Conclusion**:
- The correct answer is **Option 2: Liquids and Gases**. Both of these categories fit the definition of fluids due to their ability to flow and lack of a fixed shape.