Prafulla Chaki and Khudiram Bose are known for their attempt to assassinate which British official?

The correct answer is Douglas Kingsford.

Prafulla Chaki and Khudiram Bose were prominent young revolutionaries associated with the Jugantar group in Bengal who took part in the Indian independence movement.

They are famous for the Alipore bomb conspiracy case, also known as the Muzaffarpur bombing, which took place on April 30, 1908. Their target was Douglas Kingsford, the Chief Presidency Magistrate of Calcutta (later transferred to Muzaffarpur as District Judge). Kingsford had become notorious for handing out harsh and cruel punishments to young nationalist activists and students who participated in the Swadeshi movement.

On the evening of April 30, 1908, Chaki and Bose threw a bomb at a carriage they believed was carrying Kingsford. However, the carriage was actually carrying the wife and daughter of barrister Pringle Kennedy, both of whom lost their lives in the attack. Kingsford escaped unharmed.

Following the incident, Prafulla Chaki committed suicide by shooting himself to avoid arrest by the British police. Khudiram Bose was arrested, tried, and subsequently hanged on August 11, 1908, at the young age of 18, becoming one of the youngest martyrs of the Indian independence movement.