निम्नलिखित में से किसने 'प्राथमिक समूह' (Primary Group) की अवधारणा को विकसित और प्रस्तुत किया था?

The Dandi March, also known as the Salt Satyagraha, was led by which influential leader?

Which act formally granted independence to India, marking the end of British rule?

Who was the key figure in establishing the Indian National Congress?