## **Core Concept**
The incubation period of a disease is the time between exposure to the pathogen and the onset of symptoms. Measles, caused by the measles virus, is a highly contagious viral infection.

## **Why the Correct Answer is Right**
The correct incubation period for measles is approximately 10 to 14 days. This duration accounts for the time from exposure to the measles virus to the appearance of the characteristic rash and other symptoms. The measles virus replicates in the respiratory tract and spreads to lymphoid tissues before causing a systemic infection.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Typically represents a shorter period than the known incubation period for measles.
- **Option B:** Could be considered within the range but is not the most accurate representation of the typical incubation period for measles.
- **Option D:** Represents a longer period than the commonly accepted incubation period for measles.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that individuals with measles are contagious from 4 days before the onset of the rash to 4 days after. The classic triad of symptoms includes cough, coryza (runny nose), and conjunctivitis, along with the characteristic rash.

## **Correct Answer:** C. 10-14 days.