Correct Answer: Northern part of West Champaran
Subject: 2025
Explanation: <b>Key Fact</b><br>The Someshwar Range is located in the northernmost part of the West Champaran district in Bihar, forming a natural border with Nepal in the Shiwalik foothills.<br><br><b>Additional Info</b><br>Topic: Physiography of Bihar.<br><br><b>Why the other options are wrong</b><br>Option A: Correct.<br>Option B: Banka lies in southeast Bihar with residual granitic hills.<br>Option C: Gaya contains residual hills like Pretshila, Ramshila, Brahmayoni.<br>Option D: Rohtas contains the Kaimur plateau.<br><br><b>Exam Trick</b><br>Someshwar Fort is the highest peak in Bihar, situated in West Champaran.<br><br><b>Final Answer</b><br>Option A — Northern part of West Champaran.