When was Ambala established as a military cantonment?

The correct answer is: A. 1811.

Ambala was established as a military cantonment in 1811 by the British East India Company. The cantonment was built to house British troops and their families, and it quickly became an important military base in the region. Ambala was also a major center of trade and commerce, and it played a significant role in the development of the Indian subcontinent.

The other options are incorrect because:

• Option B, 1843, is the year when the Battle of Aliwal took place near Ambala. The battle was fought between the British and the Sikhs, and it resulted in a British victory.
• Option C, 1856, is the year when the Indian Rebellion of 1857 began. The rebellion was a major uprising against British rule in India, and it resulted in the deaths of thousands of people.
• Option D, 1901, is the year when the British Raj was established in India. The Raj was a period of British rule in India that lasted from 1858 to 1947.