What is Language-in-education policy known as ?

Correct option is D

Three language formula
Language-in-education policy is commonly known as the "Three Language Formula." This policy, especially in the Indian education system, advocates for the study of three languages by students. It typically includes the mother tongue or regional language, Hindi (in non-Hindi-speaking states), and English. The idea behind this formula is to promote multilingual proficiency, which is considered important for national unity and global communication.