The correct answer is: B) Military action (Operation Polo)
Hyderabad State was a princely state in India that existed from 1724 to 1948. It was ruled by the Nizam of Hyderabad, who was an independent ruler. In 1947, India gained independence from British rule. The Nizam of Hyderabad wanted to remain independent, but the Indian government wanted Hyderabad to join India. The Nizam refused to join India, and the Indian government sent troops into Hyderabad in 1948. The Indian troops defeated the Nizam’s forces, and Hyderabad became part of India.
Option A: Negotiated settlement is not the correct answer because the Nizam of Hyderabad refused to negotiate with the Indian government.
Option C: Popular referendum is not the correct answer because there was no popular referendum on whether Hyderabad should join India.
Option D: Act of British Parliament is not the correct answer because the British Parliament did not pass any act that made Hyderabad part of India.