Which of the Railways attained the status of World Heritage site by UNESCO? A. Darjeeling Himalayan Railway B. Nilgiri Mountain Railway C. Kalka–Shimla Railway D. All the above
D [All the above] Explanation: Three railways, the Darjeeling Himalayan Railway, the Nilgiri Mountain Railway, and the Kalka–Shimla Railway, are collectively designated as a UNESCO World Heritage Site under the name Mountain Railways of India