A disease caused by one of the smallest virus is:

Options

A. mumps
B. Measles
C. Poliomyelitis
D. trachoma

Answer

To solve the question "A disease caused by one of the smallest virus is:", we can follow these steps:

### Step 1: Identify the Options
The options provided are:
- a. Mumps
- b. Measles
- c. Poliomyelitis
- d. Trachoma

### Step 2: Understand Each Disease
- **Mumps**: Caused by the mumps virus, which is larger than poliovirus.
- **Measles**: Caused by the measles virus, which is also larger than poliovirus.
- **Poliomyelitis**: Caused by the poliovirus, which is known to be one of the smallest viruses.
- **Trachoma**: Caused by Chlamydia trachomatis, which is a bacterium, not a virus.

### Step 3: Focus on Poliomyelitis
Poliomyelitis, commonly known as polio, is caused by the poliovirus. The poliovirus is approximately 30 nanometers in diameter, making it one of the smallest known viruses. It has a simple structure consisting of RNA and a protein coat.

### Step 4: Conclusion
Based on the information about the size and characteristics of the viruses causing the diseases listed, the correct answer is:
**c. Poliomyelitis**

### Final Answer
The disease caused by one of the smallest viruses is **Poliomyelitis (option C)**.

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