The correct answer is Hyderabad. After attaining Independence, the princely states were given three options to decide their future, i. e. , accede to India, accede to Pakistan, or remain independent. By 1948 most of the Princely States had acceded to India but the state of Hyderabad had chosen to join neither Pakistan nor India. Following various events in Hyderabad like the rise of razakars and the Telangana uprising, the Indian government decided to undertake a military operation to annex Hyderabad. On 13th September 1948, the Indian Army launched an attack on Hyderabad; this operation was named ‚¬ËœOperation Polo‚¬„¢. The Indian Army, in a 5-day battle, annexed Hyderabad from the Nizam and integrated it into the territory of India. Hence, Hyderabad is the state associated with Operation Polo.