Phase-III of population growth in India is marked by a reduction in the death rate due to improvements in medical facilities, healthcare services, and living conditions. The advancement in healthcare infrastructure and better living conditions, such as improved sanitation and access to clean water, contributed to a decline in mortality rates. This phase is characterized by continued population growth, but at a decreasing rate as the country moves towards stabilizing its population.
- Option (A) is incorrect because although high female literacy is a key factor in population control, it is not the primary characteristic of Phase-III.
- Option (C) is incorrect because the Great Economic Depression and World War II had no significant role in the specific characteristics of India's Phase-III population growth.
- Option (D) is incorrect as low population growth and low net increase are characteristics of later stages (Phase-IV) of population growth.
Thus, the correct answer is (B) Improvisation in medical facilities and living conditions.