Which among the following events happened earliest?

1. A

   Swami Dayanand established Arya Samaj.

   (a) Swami Dayanand established Arya Samaj. Arya Samaj was founded at Bombay in 1875—later than Nil Darpan. This option is not the earliest event. This option is not the key.

2. B

   Dinabandhu Mitra wrote Neeldarpan.

   (b) Dinabandhu Mitra wrote Neeldarpan. The play was published in 1860, the earliest date among the four listed events. This option is the official key.

3. C

   Bankim Chandra Chattopadhyay wrote Anandmath.

   (c) Bankim Chandra Chattopadhyay wrote Anandmath. Anandamath appeared in 1882, after both Nil Darpan and Satyendranath’s ICS success. This option is not the key.

4. D

   Satyendranath Tagore became the first Indian to succeed in the Indian Civil Services Examination.

   (d) Satyendranath Tagore became the first Indian ICS officer. He passed in 1863 (joined 1864)—after 1860. This option is not the key.

Summary. Official key is (b). Chronology of the four events: Nil Darpan (1860), Satyendranath Tagore’s ICS (1863/64), Arya Samaj (1875), Anandamath (1882). The earliest is therefore Dinabandhu Mitra’s play. Options that pick 1875, 1882 or the ICS success are later. The stored letter is (b).