## **Core Concept**
The question assesses the understanding of the immunization schedule recommended by the World Health Organization (WHO) and various national health guidelines. Specifically, it tests knowledge of vaccines administered to infants, focusing on the schedule for polio and BCG vaccines, and identifying the next appropriate vaccine.

## **Why the Correct Answer is Right**
The correct answer, **DTP (Diphtheria, Tetanus, and Pertussis) vaccine**, is appropriate at 1 year of age as part of the routine immunization schedule. Given that the child received BCG (Bacillus Calmette-Guérin) at birth, which protects against tuberculosis, and polio vaccine at birth (likely the first dose of the oral poliovirus vaccine, OPV), the next vaccine in the series would be DTP. This vaccine is crucial for protecting against diphtheria, tetanus, and pertussis.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not specified, but if it suggests not giving any vaccine, that would be incorrect as vaccinations are essential for immunity.
- **Option B:** Without a specific vaccine listed, it's hard to directly address, but if it implies an incorrect vaccine for this age group, it would be wrong based on the standard immunization schedule.
- **Option C:** Similarly, without specifics, if this option suggests an inappropriate vaccine for a 1-year-old who has already received BCG and polio vaccine at birth, it would be incorrect.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is the typical immunization schedule: BCG and Hepatitis B at birth, followed by a series of vaccines including DTP, polio, and others at specific intervals. For a 1-year-old who started with BCG and polio at birth, ensuring they are on track with DTP, measles, and other vaccines according to the local immunization schedule is crucial.

## **Correct Answer: D. DTP.**