Who among the following was not associated with the Kakori case?

Concept: The Kakori train robbery (9 August 1925) was carried out by revolutionaries of the Hindustan Republican Association (HRA), who looted a train carrying government treasury money near Kakori, Uttar Pradesh; those involved were later tried in the separate Kakori Conspiracy Case (1926-27). Revolutionary movements of this period operated as distinct, separately organised groups tied to specific incidents and later tried in separate court cases -- a person's role in one uprising does not automatically extend to another.

Application: Ram Prasad Bismil, Ashfaqulla Khan and Rajendra Lahiri were core HRA members who planned and carried out the Kakori train robbery; all three (along with Roshan Singh) were tried in the Kakori Conspiracy Case (1927) and executed in December 1927. Surya Sen ('Masterda'), by contrast, organised and led the Chittagong Armoury Raid on 18 April 1930 as head of the Indian Republican Army's Chittagong branch -- a different organisation and a different incident, five years after Kakori.

• Ashfaqulla Khan -- planned and took part in the Kakori robbery itself; convicted and executed in the Kakori Conspiracy Case.

• Rajendra Lahiri -- took part in the Kakori robbery and was tried and executed in the Kakori Conspiracy Case.

• Ramprasad Bismil -- chief organiser of the Kakori robbery and lead accused in the Kakori Conspiracy Case.

• Surya Sen -- organised and led the separate Chittagong Armoury Raid (1930) as head of a different organisation; had no role in the Kakori robbery or its conspiracy trial.

Cross-check: Separate trial records confirm this: the Kakori accused were convicted in the Kakori Conspiracy Case of 1927, while Surya Sen was tried by a special tribunal in 1933 and executed in January 1934 for the Chittagong Armoury Raid case -- two distinct proceedings years apart, ruling out any Kakori connection for Surya Sen.