निम्नलिखित में से किसे दुनिया की पहली व्यावसायिक रूप से सफल वेब-आधारित ईमेल सेवा के रूप में व्यापक रूप से मान्यता प्राप्त 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?