The correct answer is (a) Bhotia.
The Bhotia are an ethnic group native to the Himalayan region. They are found in India, Nepal, and Bhutan. The Bhotia are traditionally traders and herders. They have a long history of trade with Tibet. The Indo-China war of 1962 led to the closure of the border between India and Tibet. This had a significant impact on the Bhotia people, as it disrupted their traditional trade routes.
The Raji are an ethnic group native to the Kumaon region of Uttarakhand. They are traditionally farmers and herders. The Raji have a long history of contact with Tibet. However, they did not have a significant trade relationship with Tibet before the Indo-China war of 1962.
The Boksa are an ethnic group native to the Garhwal region of Uttarakhand. They are traditionally farmers and herders. The Boksa have a long history of contact with Tibet. However, they did not have a significant trade relationship with Tibet before the Indo-China war of 1962.
The Jaunsari are an ethnic group native to the Jaunsar-Bawar region of Uttarakhand. They are traditionally farmers and herders. The Jaunsari have a long history of contact with Tibet. However, they did not have a significant trade relationship with Tibet before the Indo-China war of 1962.