Explanation:

- Rabindranath Tagore used the pseudonym 'Bhanusingha.' He was an influential poet and writer, known worldwide for his contributions to literature.

- Bankim Chandra Chattopadhyay was another noted Bengali writer, known for composing the song "Vande Mataram," but he didn't use the pseudonym 'Bhanusingha.'

- Sunil Gangopadhyay was a modern Indian poet in Bengali literature, not associated with the pseudonym in question.

- Michael Madhusudan Dutt was a pioneering Indian poet but known for introducing the sonnet into Bengali literature, not for using 'Bhanusingha.'