Explanation

Raja Man Singh Tomar of Gwalior (r. 1486–1516) is credited with the introduction and popularisation of the Dhrupad form of Hindustani classical music — his court nurtured it and the 'Man Kautuhal' tradition. Tansen (option B) was the later Mughal-era maestro of Akbar's court; Naik Gopal and Shaikh Bahauddin of Barnawa (options C, D) are not credited with Dhrupad's founding. Hence option A.