The correct option is C Parts of Arunachal Pradesh
After a failed revolt in Tibet since China occupied it, thousands of Tibetans escaped along with the Dalai Lama. The Dalai Lama sought refuge in India which he was given willingly. This caused a conflict between China and India.
China claimed the Aksai-chin area in the Ladakh region and much of Arunachal Pradesh.
The region of Gujarat was never a bone of contention between India and China.