निम्नलिखित में से कौन सी अवधारणा उत्पाद की एक अतिरिक्त इकाई जोड़ने या उत्पादित करने पर होने वाली लागत का प्रतिनिधित्व करती 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?