Correct answer: A. Nana Sahib
Explanation: The direct answer is option A, Nana Sahib. The Revolt of 1857 had different leaders in different centres. Nana Sahib was the principal leader associated with Kanpur, also called Cawnpore. Step by step: first identify the centre—Kanpur; then match its leading figure—Nana Sahib; therefore option A is correct. Option B, Kunwar Singh, is mainly associated with the Bihar region, especially Jagdishpur. Option C, Begum Hazrat Mahal, led resistance in Lucknow and Awadh. Option D, Khan Bahadur Khan, was associated mainly with Bareilly. These leaders all belonged to the Revolt of 1857, which can make the question confusing, but the location is the deciding clue. Memory trick: Kanpur—Nana Sahib; Lucknow—Begum Hazrat Mahal; Bihar—Kunwar Singh; Bareilly—Khan Bahadur Khan.