Assertion: Infectious disease are very common.
Reason: These disease are easily transmitted from one person to another.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Answer

To analyze the assertion and reason provided in the question, we can break down the information as follows:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Infectious diseases are very common." This is true as infectious diseases, such as the common cold, chickenpox, and others, are frequently encountered in the population.

2. **Understanding the Reason**:
- The reason states that "These diseases are easily transmitted from one person to another." This is also true, as infectious diseases are typically caused by pathogens (bacteria, viruses, fungi) that can spread through various means, such as direct contact, airborne transmission, or bodily fluids.

3. **Connecting Assertion and Reason**:
- The reason provided supports the assertion. Since infectious diseases are easily transmitted, it logically follows that they would be common in the population. For example, diseases like the flu or common cold spread rapidly, leading to high incidence rates.

4. **Conclusion**:
- Both the assertion and the reason are correct, and the reason effectively justifies the assertion. Therefore, we can conclude that the statement is valid.

### Final Answer:
Both the assertion and the reason are correct, and the reason supports the assertion.