The Indian states bordering Nepal are Bihar, Uttaranchal (now Uttarakhand), Uttar Pradesh, Sikkim, and West Bengal. These states form India's northern boundary with Nepal along the Himalayan region. Option B is incorrect as it lists northeastern states (Mizoram, Meghalaya, Tripura, Assam) which border Bangladesh and Myanmar, not Nepal. Option C is incorrect because Tripura and Assam do not border Nepal. Option D is incorrect as Mizoram is in the northeast.