Which of the following disease is 100% fatal and mode of transmission is infected animals?

Options

A. AIDS
B. Rebies
C. Tetanus
D. Hepatitis-B

Answer

To solve the question about which disease is 100% fatal and transmitted by infected animals, we can analyze each option provided:

1. **AIDS**:
- AIDS (Acquired Immunodeficiency Syndrome) is primarily transmitted through sexual contact and sharing of needles. It is not transmitted by animals. Therefore, AIDS is not the correct answer.

2. **Rabies**:
- Rabies is a viral disease that is transmitted through the bite of an infected animal, commonly through dogs. Once symptoms appear, rabies is almost always fatal. This makes rabies a strong candidate for the answer.

3. **Tetanus**:
- Tetanus is caused by a bacterial infection that occurs when the bacteria enter the body through wounds or cuts, often from contaminated objects. There is no involvement of animals in its transmission. Thus, tetanus is not the correct answer.

4. **Hepatitis B**:
- Hepatitis B is a viral infection that affects the liver and is transmitted through contact with infectious body fluids, such as blood and sexual contact. It is not transmitted by animals. Therefore, hepatitis B is also not the correct answer.

After analyzing all the options, we conclude that the disease that is 100% fatal and transmitted by infected animals is **Rabies**.

### Final Answer:
**Rabies**