## Core Concept
Mission Indradhanush is a flagship program of the Government of India aimed at strengthening and re-energizing the immunization program and to achieve full immunization coverage for all children and pregnant women at a rapid pace. The program targets to immunize all children under 2 years of age and pregnant women against seven vaccine-preventable diseases.

## Why the Correct Answer is Right
The seven vaccine-preventable diseases targeted under Mission Indradhanush are:
- Diphtheria
- Whooping Cough
- Tetanus
- Poliomyelitis (Polio)
- Tuberculosis (TB)
- Measles
- Hepatitis B

## Why Each Wrong Option is Incorrect
- **Option A:** Diphtheria is one of the diseases covered under Mission Indradhanush, so this option is incorrect.
- **Option B:** Whooping Cough is also a target disease, making this option incorrect.
- **Option C:** Tetanus is another disease covered by the mission, which makes this option incorrect.

## Why Option D is Correct
- **Option D:** Although the specific disease in option D isn't mentioned, given that the other options (A, B, and C) are diseases covered under the mission, and if option D represents a disease not included in the list of seven targeted diseases (Diphtheria, Whooping Cough, Tetanus, Poliomyelitis, Tuberculosis, Measles, and Hepatitis B), then it would be the correct answer as an exception.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Mission Indradhanush focuses on seven major vaccine-preventable diseases. Knowing these diseases is crucial for understanding the scope of the mission and for public health practices.

## Correct Answer: D.