Explanation: Mahatma Gandhi amongst the following had called Rabindranath Tagore as THE GREAT SENTINEL. Rabindranath Tagore was a key figure of the Bengal Renaissance. He started writing at an early age and by the turn of the century had become a household name in Bengal as a poet, a songwriter, a playwright, an essayist, a short story writer and a novelist. In 1913 he was awarded the Nobel Prize for Literature and his verse collection Gitanjali came to be known internationally. At about the same time he founded Visva-Bharati, a university located in Santiniketan, near Kolkata. Called the ‘Great Sentinel’ of modern India by Mahatma Gandhi, Tagore steered clear of active politics but is famous for returning his knighthood as a gesture of protest against the Jallianwala Bagh massacre in 1919.