The correct answer is (a). The “Seven Years Devastation” refers to the period of Burmese occupation of Manipur from 1819 to 1826. The Burmese invaded Manipur in 1819 and occupied the kingdom for seven years. During this time, the Burmese looted and destroyed much of the kingdom, and many Manipuris were killed or enslaved. The Burmese occupation had a devastating impact on Manipur, and it took the kingdom many years to recover.
The other options are incorrect. (b) British punitive expeditions were a series of military campaigns that the British launched against Manipur in the 19th century. These expeditions were carried out in response to Manipuri raids on British territory. (c) The Great Famine was a famine that occurred in Manipur in the 18th century. The famine caused widespread death and suffering in the kingdom. (d) Religious persecution in Manipur has occurred at various times in the kingdom’s history. However, it is not the period that is referred to as the “Seven Years Devastation”.