Explanation:

- Tulsidas Borkar was a renowned Indian classical musician and a virtuoso harmonium player.

- He was awarded the Padma Shri in 2016 for his contributions to Indian music.

- Option 4, Harmonium: This is the correct option. Tulsidas Borkar was acclaimed for his expertise and innovative techniques in playing the harmonium.

- Option 1, Nadhaswaram: This is a traditional South Indian instrument, played mainly in the Carnatic music realm, not associated with Tulsidas Borkar.

- Option 2, Shehnai: A wind instrument used in North Indian music, famously played by Ustad Bismillah Khan.

- Option 3, Bansuri: This is a bamboo flute used in Hindustani classical music, famously associated with Pandit Hariprasad Chaurasia.