स्वतंत्रता-पूर्व अवधि के दौरान बिहार में समाजवादी विचारधारा के प्रसार का मुख्य श्रेय निम्नलिखित में से किस कारक को दिया जा सकता है?

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?