Explanation:

- Option 1: Gangubai Hangal

- Gangubai Hangal was a legendary Hindustani classical vocalist from Karnataka, India. She was renowned for her command over the Khayal genre.

- Not associated with Carnatic music, she performed primarily in the Kirana Gharana style of Hindustani music.

- Option 2: GN Balasubramaniam

- Correct Answer

- GN Balasubramaniam was a prominent figure in Carnatic music. Known for his innovative approach, he was a celebrated vocalist who significantly influenced Carnatic music’s performance style.

- Option 3: Kaushiki Chakraborty

- Kaushiki Chakraborty is a contemporary Indian classical vocalist known for her performances in Hindustani classical music.

- She belongs to the Patiala Gharana and is not associated with Carnatic music.

- Option 4: Girija Devi

- Girija Devi was a profound Indian classical singer but primarily performed in the Hindustani tradition, especially known for her Thumris.

- She was not part of the Carnatic music tradition.