Identify the main source of our knowledge about the rebels in 1857?

The correct answer is Option (1) → Azamgarh Proclamation

Very few records of the rebels of 1857 have survived, so their own proclamations are precious. The Azamgarh Proclamation of 25 August 1857 is one of the main sources of our knowledge about what the rebels wanted. It called on Hindus and Muslims alike to rise against British rule, and set out, section by section, the grievances of groups such as the zamindars and the merchants.