In which landmark case did a five-judge Constitution Bench of the Supreme Court held that 'imparting education cannot be treated as a trade or business' under Article 19(1)(g)?

The 'Drain of Wealth' theory was propounded by which Indian nationalist leader?

Which event is considered the turning point in Mahatma Gandhi's leadership in the Indian independence movement?

Which African leader is known for his non-violent opposition to colonial rule?