The British might have introduced or strengthened surveillance measures in Sikkim after the Revolt to:

The correct answer is: All of the above.

The British might have introduced or strengthened surveillance measures in Sikkim after the Revolt to:

• Monitor potential dissent: The British were concerned about the possibility of further uprisings in Sikkim, and they wanted to be able to identify and suppress any potential threats before they could materialize.
• Gather intelligence on neighboring regions: Sikkim is located in a strategically important position, and the British wanted to be able to gather intelligence on the activities of other powers in the region, such as Russia and China.
• Prevent communication with rebels: The British were also concerned about the possibility of rebels in Sikkim communicating with rebels in other parts of India, and they wanted to be able to prevent this from happening.

The British had a long history of intervening in the affairs of Sikkim, and they had a strong interest in maintaining control over the region. The Revolt of 1857 had shown the British that they could not take their control of India for granted, and they were determined to prevent any further uprisings from happening. The introduction or strengthening of surveillance measures in Sikkim was one way in which the British sought to achieve this goal.