Swine flu, dengue and chikungunya are

Options

A. bacterial diseases
B. viral diseases
C. helminthic diseases
D. fungal diseases.

Explanation

To answer the question, "Swine flu, dengue, and chikungunya are," we will analyze each disease and determine their classifications.

### Step-by-Step Solution:

1. **Identify the causative agents of each disease**:
- **Swine Flu**: This disease is caused by the H1N1 influenza virus, which is a type of virus.
- **Dengue**: This disease is caused by the dengue virus, which also falls under the category of viruses.
- **Chikungunya**: This disease is caused by the chikungunya virus, again a type of virus.

2. **Classify the diseases based on their causative agents**:
- Since all three diseases (swine flu, dengue, and chikungunya) are caused by viruses, they can be classified as viral diseases.

3. **Evaluate the options provided**:
- **Bacterial Diseases**: This option is incorrect because none of the diseases are caused by bacteria.
- **Viral Diseases**: This option is correct as all three diseases are caused by viruses.
- **Helminthic Diseases**: This option is incorrect because helminthic diseases are caused by parasitic worms, not viruses.
- **Fungal Diseases**: This option is also incorrect as fungal diseases are caused by fungi.

4. **Conclusion**: Based on the analysis, the correct classification for swine flu, dengue, and chikungunya is that they are all viral diseases.

### Final Answer:
Swine flu, dengue, and chikungunya are **viral diseases**.