The correct answer is option 'B' - Jawaharlal Nehru. Nehru's book "The Discovery of India" is a comprehensive account of India's history, culture, and philosophy. It was first published in 1946 and has since become a widely read and influential work.

Jawaharlal Nehru was the first Prime Minister of India and a prominent leader in the Indian independence movement. He played a crucial role in shaping modern India and was known for his deep understanding of the country's history and civilization. "The Discovery of India" was written during his imprisonment in 1942-1946 as a response to his daughter's request for a book on Indian history.

Here is a detailed explanation of why Jawaharlal Nehru wrote "The Discovery of India":

1. Historical Context:
- Nehru was imprisoned by the British colonial government during the Quit India Movement, a major civil disobedience movement for independence.
- During his imprisonment, Nehru had ample time to reflect on India's history, culture, and philosophy.

2. Nehru's Vision of India:
- Nehru was deeply committed to the idea of a modern, democratic, and secular India.
- He believed that a strong understanding of India's rich past was essential for shaping the future of the nation.
- Nehru wanted to provide Indians with a comprehensive account of their heritage, which would instill a sense of pride and unity among the people.

3. Scope and Content of the Book:
- "The Discovery of India" covers a vast range of topics, including ancient history, religions, philosophy, art, literature, and the freedom struggle.
- Nehru explores India's civilizational achievements, its interactions with other cultures, and the challenges it faced under colonial rule.
- The book also delves into Nehru's own reflections on nationalism, socialism, and the role of science and technology in India's development.

4. Impact and Significance:
- "The Discovery of India" has had a profound impact on generations of Indians, shaping their understanding of their country's past and inspiring a sense of national pride.
- The book has been translated into several languages and continues to be widely read and studied.
- Nehru's portrayal of India as a diverse yet united nation, with a rich cultural heritage, resonated with many Indians and influenced their perception of their own identity.

In conclusion, "The Discovery of India" was written by Jawaharlal Nehru during his imprisonment as a comprehensive account of India's history, culture, and philosophy. It reflects Nehru's vision of a modern and united India and has had a significant impact on shaping the understanding of Indian identity and heritage.