The correct answer is `Bharatmata by Abanindranath Tagore`. Sister Nivedita, an Irish teacher and disciple of Swami Vivekananda, regarded this artwork as the `first masterpiece of Indian art` because of its distinct representation of Indian nationalistic spirit. Option 2, `Arjuna and Subhadra by Raja Ravi Varma`, and option 3, `Sita in Captivity in Lanka by Abanindranath Tagore`, are not correct as they were not identified as such by Sister Nivedita. The last option `Sati by Nandalal Bose` is also not correct because, while Nandalal Bose was a prominent artist of the Bengal School of Art, like Abanindranath, his artwork `Sati` was not hailed as the `first masterpiece of Indian art` by Sister Nivedita.