The correct option is: Only B
Explanation:
- Demographic transition refers to the shift from high birth and death rates to low birth and death rates, typically observed as a country undergoes economic development.
- In the context of India, mortality rates have been successfully reduced (Option A). However, birth rates in India have not reduced significantly, which is a key factor preventing the completion of the demographic transition (Option B). This is why the correct option is "Only A."