The correct answer is: A. Kashmir
Kashmir is a region in the northwestern Himalayas. It is divided between India, Pakistan, and China. The Indian-administered part of Kashmir is known as Jammu and Kashmir. The climate of Kashmir is sub-tropical, with warm summers and mild winters. The average temperature in Kashmir ranges from 10°C in winter to 30°C in summer. The region receives an average annual rainfall of 1,000 mm.
The Jammu region is located in the south of Jammu and Kashmir. The climate of Jammu is temperate, with warm summers and cold winters. The average temperature in Jammu ranges from 15°C in winter to 35°C in summer. The region receives an average annual rainfall of 750 mm.
The Ladakh region is located in the north of Jammu and Kashmir. The climate of Ladakh is cold desert, with cold winters and cool summers. The average temperature in Ladakh ranges from -20°C in winter to 20°C in summer. The region receives an average annual rainfall of 100 mm.
Therefore, the only region of Jammu and Kashmir that comes under the sub-tropical climatic zone is Kashmir.