Question: what mutiny in India was thwarted by MI5(b) during World War I?
Context: The 1915 Singapore Mutiny, also known as the 1915 Sepoy Mutiny or the Mutiny of the 5th Light Infantry, was a mutiny involving up to half of a regiment of 850 sepoys (Indian soldiers) against the British in Singapore during the First World War, linked with the 1915 Ghadar Conspiracy.  The mutiny, on 15 February 1915, lasted nearly seven days.  It resulted in the deaths of eight British officers and soldiers, two Malay officers and one soldier, 14 British civilians, five Chinese and Malay civilians and one German internee before it was finally quelled by British forces and Allied naval detachments. The MI5(g), or the MI5 G section, was a branch of MI5 that was formed during World War I to address the wartime espionage operation by the Indian revolutionary movement in Europe.  The department arose by renaming the MO5(g), which was renamed MI5(g) in 1916.  The MI5 itself, working under Vernon Kell, had a number of India experts at the beginning of the war.  In September 1916, a special section, the MI5(d), section was formed to operate counter-espionage networks throughout the British Empire.  Another subsection, the MI5(b), was formed in January 1917 to deal specifically with Indians and "other oriental races".  The MI5(g) had 27 officers in its staff, eight of whom had served in India before the war.  Among them were ex-Indian civil servants including Robert Nathan and H. L. Stephenson.  The main emphasis of this counter-espionage network was to prevent the subversion of Indian troops in the European theatre.  The organisation, especially under Nathan, worked closely with the Special Branch of the Scotland Yard in Britain and with the Indian Political Intelligence Office headed by John Wallinger, which operated a network of spies in neutral Switzerland which a number of the Indian revolutionaries and members of the Berlin Committee used as a base. The Caine Mutiny is a 1954 American film.  A fictional Navy drama set in the Pacific during World War II, it was directed by Edward Dmytryk and produced by Stanley Kramer, and stars Humphrey Bogart, José Ferrer, Van Johnson, and Fred MacMurray.  The film is based on "The Caine Mutiny," the 1951 Pulitzer Prize-winning novel written by Herman Wouk.  It depicts the events on board a fictitious World War II U.S. Navy destroyer minesweeper and a subsequent court-martial for mutiny. The 1919 Southampton mutiny was a mutiny in the British Army which occurred in January 1919 in the aftermath of World War I.  The soldiers, after being misinformed that they were being transported to Southampton to be demobilized, were then ordered to board troop ships for France.  The mutiny was brought to an end without bloodshed when General Sir Hugh Trenchard threatened lethal force. The Ghadar Mutiny (Hindustani: ग़दर राज्य-क्रान्ति, غدر ریاست - کرانتی "Ġadara Rājya-krānti"), also known as the Ghadar Conspiracy, was a plan to initiate a pan-Indian mutiny in the British Indian Army in February 1915 to end the British Raj in India.  The plot originated at the onset of the First World War, between the Ghadar Party in the United States, the Berlin Committee in Germany, the Indian revolutionary underground in British India and the German Foreign Office through the consulate in San Francisco.  The incident derives its name from the North American Ghadar Party, whose members of the Punjabi Sikh community in Canada and United States were one of the most prominent participants in the plan.  It was the most prominent amongst a number of plans of the much larger Hindu–German Mutiny, formulated between 1914 and 1917 to initiate a Pan-Indian rebellion against the British Raj during World War I.  The mutiny was planned to start in the key state of Punjab, followed by mutinies in Bengal and rest of India.  Indian units as far as Singapore were planned to participate in the rebellion.  The plans were thwarted through a coordinated intelligence and police response.  British intelligence infiltrated the Ghadarite movement in Canada and in India, and last minute intelligence from a spy helping to crush the planned uprising in Punjab before it started.  Key figures were arrested, mutinies in smaller units and garrisons within India were also crushed. The Royal Air Force Mutiny of 1946 was a mutiny on dozens of Royal Air Force stations in India and South Asia in January 1946 over conditions of slow demobilization and conditions of service following the end of World War II.  The mutiny began at Karachi and later spread to involve nearly 50,000 men over 60 RAF stations in India and Ceylon, including the then-largest RAF base at Kanpur and RAF bases as far as Singapore. The Hindu–German Conspiracy was a series of plans between 1914 and 1917 by Indian nationalist groups to attempt Pan-Indian rebellion against the British Raj during World War I, formulated between the Indian revolutionary underground and exiled or self-exiled nationalists who formed, in the United States, the Ghadar Party, and in Germany, the Indian independence committee, in the decade preceding the Great War.  The conspiracy was drawn up at the beginning of the war, with extensive support from the German Foreign Office, the German consulate in San Francisco, as well as some support from Ottoman Turkey and the Irish republican movement.  The most prominent plan attempted to foment unrest and trigger a Pan-Indian mutiny in the British Indian Army from Punjab to Singapore.  This plot was planned to be executed in February 1915 with the aim of overthrowing British rule over the Indian subcontinent.  The February mutiny was ultimately thwarted when British intelligence infiltrated the Ghadarite movement and arrested key figures.  Mutinies in smaller units and garrisons within India were also crushed. This is a list of members of the British Free Corps.  It is based on the list printed in Appendix 5 of Adrian Weale.  "Renegades: Hitler's Englishmen".  London: Weidenfeld & Nicolson, 1994.  ISBN  .  The Corps (German: "Britisches Freikorps" ) was a unit of the Waffen SS during World War II consisting of British and Dominion prisoners of war who had been recruited by the Nazis.  The Corps used the SS rank structure.  The column 'MI5 no.'  refers to the number allocated to the member in question in MI5's Report on the British Free Corps dated 27 March 1945, which is printed in Appendix 1 of 'Renegades'.  Starting in February 1944, BFC members were ordered to adopt aliases for official purposes, although several declined to do so. Eric Arthur Roberts (18 June 1907 - 17 or 18 December 1972) was an MI5 agent during the Second World War under the alias Jack King.  By posing as a Gestapo agent, and infiltrating fascist groups in the UK, Roberts was able to prevent secret information finding its way to Germany.  Roberts continued to work for the security services after the war, notably in Vienna, but it was a time of great anxiety in the services due to the suspicions surrounding double agents such as the Cambridge Five.  Roberts never felt completely accepted by MI5 due to his different social background, and moving to a less active desk role did not suit him so well as his wartime role. The Terrace mutiny was a revolt by Canadian soldiers based in Terrace, British Columbia during the Second World War.  The mutiny, which began on November 24, 1944, and ended on November 29, 1944, was the most serious breach of discipline in Canadian military history.  The mutiny was triggered by the rumour that conscript soldiers based on the home front would be deployed overseas.
Answer: The February mutiny