Which city in Telangana was developed as a major military cantonment by the British?

The correct answer is C) Secunderabad.

Secunderabad was developed as a major military cantonment by the British in the early 19th century. It was named after the Mughal emperor, Aurangzeb, who was also known as Secunder. The city was originally a small village, but it grew rapidly under British rule. It became a major military base and a center of trade and commerce.

Hyderabad was the capital of the Nizam of Hyderabad, an independent princely state. It was a major cultural and educational center. Warangal was an important city in the Kakatiya dynasty. It was a center of trade and commerce. Karimnagar was a small town. It was not developed as a major military cantonment by the British.