In the early nineteenth century, __________ travelled through the Rajmahal Hills.

Francis Buchanan

The correct answer is Option (2) → Francis Buchanan

Francis Buchanan, also known as Francis Buchanan-Hamilton, was a Scottish physician, naturalist, and geographer who traveled through various regions of India in the early nineteenth century. He conducted extensive surveys, including botanical and ethnographic studies. Among his journeys, he traveled through the Rajmahal Hills. Buchanan's work contributed significantly to the understanding of India's flora, fauna, and various aspects of its natural history. His surveys and observations were valuable in documenting and cataloging the natural and cultural diversity of the regions he visited.

So, the correct option is [2].