संस्थागत रूप से 'गोत्र' व्यवस्था सबसे पहले किस ऐतिहासिक काल में स्थापित हुई थी?

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?