The correct option is D All of the above
Maharaja Sawai Jai Singh of Jaipur who was also an astronomer built the Jantar Mantar. Jantar Mantar has 19 instruments out of which Samrat Yantra, Jai Prakash Yantra, Ram Yantra, Chakra Yantra, Dakshin Mural Yantra, Digamya Yantra, Disha Yantra, Kanali Yantra are prominent.