The correct answer is D. Col. Camalc.
Capt. Alexander, Lt. Thompson, and Lt. Reid were all involved in suppressing the Santhal Revolt in 1856. Col. Camalc was not involved in the revolt.
The Santhal Revolt was a major uprising by the Santhal people of India against British rule in 1855-56. The revolt was led by Sidhu and Kanhu Murmu, two Santhal brothers. The rebels were motivated by a number of factors, including British encroachment on Santhal land, high taxes, and forced labor. The revolt was brutally suppressed by the British, and thousands of Santhals were killed.
Capt. Alexander was a British officer who was stationed in the Santhal region at the time of the revolt. He was one of the commanders of the British forces that suppressed the revolt. Lt. Thompson and Lt. Reid were also British officers who were involved in suppressing the revolt.
Col. Camalc was a British officer who was not involved in the Santhal Revolt. He was stationed in a different part of India at the time of the revolt.