Madan Lal Dhingra was an Indian revolutionary who:

Assassinated a British official in London
Founded the Azad Hind Fauj
Led the Salt Satyagraha
Participated in the Quit India Movement

The correct answer is: a) Assassinated a British official in London.

Madan Lal Dhingra was an Indian revolutionary who assassinated William Hutt Curzon Wyllie, a British official in London, on 1 July 1909. He was born in Ludhiana, Punjab, British India, in 1883. He was educated at the Government College, Lahore, and then at the University of Punjab. He was a brilliant student and won several scholarships.

In 1905, he went to London to study law. He was influenced by the Indian independence movement and joined the revolutionary group Abhinav Bharat. He was arrested in 1907 for his involvement in the revolutionary activities. He was released on bail and went to Paris. He returned to London in 1909 and assassinated William Hutt Curzon Wyllie.

He was arrested and charged with murder. He was found guilty and sentenced to death. He was hanged on 17 August 1909.

Madan Lal Dhingra was a brave and patriotic Indian revolutionary. He sacrificed his life for the cause of Indian independence. He is a martyr and his sacrifice will always be remembered.

Option b) is incorrect because the Azad Hind Fauj was founded by Subhas Chandra Bose.

Option c) is incorrect because the Salt Satyagraha was led by Mahatma Gandhi.

Option d) is incorrect because the Quit India Movement was participated in by Mahatma Gandhi and other Indian leaders.