A two year old unimmunized child presents to a primary health center with fever since 5 days Mother also gives a history of rash staing behind ear-pinna a day before coming OPD. On examination, child is having running nose and congested eyes. Most probable diagnosis is:

**Core Concept**
The child's presentation with fever, rash, and respiratory symptoms suggests a viral infection, likely measles, given the age and immunization status of the child.

**Why the Correct Answer is Right**
Measles is a highly contagious viral illness caused by the measles virus. The rash typically starts on the face, behind the ears, and then spreads to other areas of the body. The child's symptoms of running nose and congested eyes are also consistent with measles. The presence of fever and rash in an unimmunized child makes measles a likely diagnosis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided.
**Option B:** This option is not provided.
**Option C:** This option is not provided.
**Option D:** This option is not provided.

**Clinical Pearl / High-Yield Fact**
Measles is a leading cause of morbidity and mortality in children worldwide, particularly in areas with low vaccination coverage. The measles rash typically appears 3-5 days after the onset of fever and can last for 3-5 days.

**Correct Answer:** C.

✓ Correct Answer: A. Measles