निम्नलिखित में से कौन सा मानक सटीक रूप से मापा, मूल्यांकित या मात्रात्मक रूप से निर्धारित नहीं किया 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?