निम्नलिखित तत्वों में से किसे मनुष्यों द्वारा सबसे पहले खोजा और उपयोग किया गया माना जाता है?

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?