Lord William Bentinck decided to make English as the medium of instruction in India.

Explanation:
Lord William Bentinck was the Governor General of India from 1828 to 1835. He is known for many significant reforms during his tenure, including the abolition of Sati, the suppression of Thuggee, and the introduction of English education in India.

The East India Company had established a system of education in India that primarily focused on Sanskrit and Arabic languages and literature. However, Bentinck realized that this system was not preparing Indians to take up administrative or professional roles in the British administration, which required proficiency in English.

Therefore, in 1835, Bentinck issued a resolution that made English the medium of instruction in all schools and colleges in India. This decision had far-reaching consequences and marked a significant turning point in India's education system.

Advantages of English education:
The decision to make English the medium of instruction in India had several advantages:

1. It opened up new opportunities for Indians to enter the British administration and other professions that were previously closed to them.

2. It helped in the dissemination of modern scientific and technological knowledge that was available only in English.

3. It facilitated communication and exchange of ideas between Indians and the British, leading to the growth of a new class of English-educated Indians who played a crucial role in India's struggle for independence.

4. It helped in the development of a common language that could bridge the linguistic and cultural barriers between different regions of India.

Conclusion:
In conclusion, Lord William Bentinck's decision to make English the medium of instruction in India was a significant step towards modernizing India's education system and preparing Indians for the challenges of the modern world.