Correct Option
The Lohit and Subansiri rivers are significant tributaries of the Brahmaputra River system. The Lohit River originates in eastern Tibet and flows through Arunachal Pradesh, entering India near Kibithu, before joining the Brahmaputra in Assam. The Subansiri River, also originating in the Himalayas of Tibet, flows through Arunachal Pradesh (specifically the Upper Subansiri and Lower Subansiri districts) before merging with the Brahmaputra in Assam. Therefore, both Lohit and Subansiri flow through Arunachal Pradesh.
Incorrect Options
The Barak River originates in the Manipur Hills. It flows through the states of Manipur, Nagaland, and Assam in India, and then enters Bangladesh, where it is known as the Surma and Kushiyara. The Barak River does not flow through Arunachal Pradesh. Consequently, options (a), (c), and (d) are incorrect as they include the Barak River as flowing through Arunachal Pradesh.