The correct answer is Option 2: Tansen. Tansen is one of the most renowned classical musicians in Indian history. He was an instrumental figure in the popularization of the Dhrupad style, a genre in Hindustani classical music.

Let`s look at the other options.

Option 1: Raja Man Singh Tomar of Gwalior. While Raja Man Singh was indeed a significant patron of the arts, including music, he himself did not introduce or popularize Dhrupad form of music.

Option 3: Naik Gopal. Naik Gopal was a notable musician, but he was not associated with the introduction or popularization of the Dhrupad form of music.

Option 4: Shaikh Bahauddin of Barnawa. Shaikh Bahauddin was a scholar and a Sufi saint but there`s no historical evidence associating him with the Dhrupad style.

Hence, Tansen is credited with the introduction and popularization of the Dhrupad form of music.