If a wave is going from one medium to another, then

Options

A. its frequency change
B. its wavelength does not change
C. its speed does not change
D. its amplitude may change

Explanation

To solve the question regarding the behavior of a wave transitioning from one medium to another, we can break down the concepts involved step by step.

### Step-by-Step Solution:

1. **Understanding Wave Properties**:
- When a wave travels through a medium, it has certain properties: frequency (f), wavelength (λ), speed (v), and amplitude (A).

2. **Transition Between Media**:
- When a wave moves from one medium (Medium 1) to another medium (Medium 2), several changes can occur.

3. **Frequency**:
- The frequency of the wave remains constant when it transitions between different media. This is because frequency is determined by the source of the wave and does not change with the medium.

4. **Wavelength**:
- The wavelength of the wave changes when it enters a new medium. This is due to the change in wave speed in different media. The relationship is given by the equation:
\[ v = f \cdot \lambda \]
- If the speed of the wave changes, the wavelength must also change to maintain the same frequency.

5. **Speed of the Wave**:
- The speed of the wave changes when it moves from one medium to another. Different media have different densities and elastic properties, which affect wave speed.

6. **Amplitude**:
- The amplitude of the wave may change when it enters a new medium. This change depends on how much energy is transmitted into the new medium. If the medium absorbs some energy, the amplitude will decrease; if it transmits energy effectively, the amplitude may remain the same or increase.

7. **Conclusion**:
- Based on the analysis, the correct statement regarding the wave transitioning from one medium to another is that its frequency remains the same, its wavelength changes, its speed changes, and its amplitude may change.

### Final Answer:
- The correct statement is: **The amplitude may change.**