The Calcutta Chromosome (1995) is a novel exploring past and future. It has been written by:

The correct option is Amitav Ghosh.

The Calcutta Chromosome is a 1995 techno-thriller novel written by the renowned Indian author Amitav Ghosh. The novel is set in Calcutta and New York, weaving together different timelines to explore themes of medicine, history, and science fiction. It won the prestigious Arthur C. Clarke Award in 1997 for its outstanding contribution to science fiction literature.

The other listed options are incorrect for the following reasons:
- Rabindranath Tagore is a legendary Bengali poet, writer, and philosopher who won the Nobel Prize in Literature in 1913, famous for works like Gitanjali.
- Raja Rao was one of the pioneering Indian English novelists, best known for his novel Kanthapura (1938).
- Mulkraj Anand was another prominent pioneer of Anglo-Indian fiction, widely known for his novels depicting the lives of the poorer castes in traditional Indian society, such as Untouchable (1935) and Coolie (1936).