When Paramoecium was subjected to X-ray, its macronucleus degenerate and one of the following stopped.
Choose the correct options.

Options

A. Locomotion, digestion, osmoregulation
B. Reproduction, digestion, locomotion
C. Reproduction, locomotion, osmoregulation
D. Reproduction, osmoregulation

Answer

To solve the question regarding the effects of X-ray exposure on Paramecium and the degeneration of its macronucleus, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Paramecium Structure**:
- Paramecium has two types of nuclei: the macronucleus and the micronucleus.
- The macronucleus is responsible for various vital functions, while the micronucleus is primarily involved in reproduction.

2. **Functions of the Macronucleus**:
- The macronucleus plays a crucial role in:
- **Locomotion**: It helps in the movement of Paramecium.
- **Digestion**: It is involved in the digestive processes.
- **Osmoregulation**: It regulates the concentration of water and maintains the internal environment.

3. **Effect of X-ray on Macronucleus**:
- When Paramecium is subjected to X-ray, the macronucleus degenerates.
- As a result, the functions associated with the macronucleus will cease.

4. **Identifying Stopped Functions**:
- Since the macronucleus is responsible for locomotion, digestion, and osmoregulation, the degeneration of the macronucleus will lead to the stopping of these functions.

5. **Choosing the Correct Option**:
- The question asks which functions stopped when the macronucleus degenerated. The correct option would be the one that includes changes in locomotion, digestion, and osmoregulation.

### Conclusion:
The correct answer is the first option, which states that changes in the concentration of water, locomotion, digestion, and osmoregulation have been affected due to the degeneration of the macronucleus.