'Neel-Darpan' by Dina Bandhu Mitra portrays the plight of _______.

'Nil Darpan' (The Indigo Mirror) is a Bengali play written by Dinabandhu Mitra in 1858–1859. The play was essential to the Indigo Revolt (1859) in Bengal, as it highlighted the severe exploitation and plight of the local peasants forced by European indigo planters to cultivate indigo under oppressive conditions. In traditional exam keys, the option "Indigo Planters" or "Indigo Cultivators" is selected to denote this specific struggle.