Who amongst the following had called Rabindranath Tagore as THE GREAT SENTINEL?

Mahatma Gandhi amongst the following had called Rabindranath Tagore 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.