Correct Option: D

Seeking revenge for the death of Lala Lajpat Rai at the hands of the police, Bhagat Singh was involved in the assassination of British police officer John Saunders. Sufficient evidence was brought against him for a conviction in the Saunders case, after trial by a Special Tribunal and appeal at the Privy Council in England. He was convicted and subsequently hanged for his participation in the murder.