डार्विन की कौन सी अवधारणा यह सुझाव देती है कि प्राकृतिक वातावरण में समूहों के जीवित रहने की क्षमता में कुछ सामाजिक विशेषताओं ने महत्वपूर्ण भूमिका निभाई?

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?