Task: Question Generation
Input (English): Passage: Just after midnight on 3 January, 200 police officers from the City of London and Metropolitan forces cordoned off the area around 100 Sidney Street. Armed officers were placed at number 111, directly opposite number 100, and throughout the night the residents of the houses on the block were roused and evacuated. Wensley woke the ground floor tenants at number 100 and asked them to fetch Gershon, claiming that she was needed by her sick husband. When Gershon appeared she was grabbed by the police and taken to the City of London police headquarters; the ground floor lodgers also evacuated. Number 100 was now empty of all residents, apart from Svaars and Sokoloff, neither of whom seemed to be aware of the evacuation.The police's operating procedure—and the law which governed their actions—meant they were unable to open fire without being fired upon first. This, along with the structure of the building, which had a narrow, winding stairwell up which police would have to pass, meant any approach to the gang members was too perilous to attempt. It was decided to wait until dawn before taking any action. At about 7:30 am a policeman knocked on the door of number 100, which elicited no response; stones were then thrown at the window to wake the men. Svaars and Sokoloff appeared at the window and opened fire at the police. A police sergeant was wounded in the chest: he was evacuated under fire across the rooftops, and taken to the London Hospital. Some members of the police returned fire, but their guns were only effective over shorter ranges, and proved ineffective against the comparatively advanced automatic weapons of Svaars and Sokoloff.By 9:00 am it was apparent that the two gunmen possessed superior weapons and ample ammunition. The police officers in charge on the scene, Superintendent Mulvaney and Chief Superintendent Stark, contacted Assistant Commissioner Major Frederick Wodehouse at Scotland Yard. He telephoned the Home Office and obtained permission from Churchill to bring in a detachment of Scots Guards, who were stationed at the Tower of London. It was the first time that the police had requested military assistance in London to deal with an armed siege. Twenty-one volunteer marksmen from the Guards arrived at about 10:00 am and took firing positions at each end of the street and in the houses opposite. The shooting continued without either side gaining any advantage.
Output (English): What is the precise name of the military detachment to which the twenty-one volunteer marksmen who arrived at about 10:00 am and took firing positions at each end of the street belonged?