निम्नलिखित में से किस संविधान संशोधन अधिनियम द्वारा भारतीय संविधान की प्रस्तावना में 'समाजवादी, पंथनिरपेक्ष और अखंडता' शब्दों को जोड़ा गया 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?