Select all that apply Which of the following were involved in the scientific management of work during the twentieth century? (Check all that apply.) Assembly line production was introduced to organize workers and their jobs. Various combinations of groups were used to complete specific tasks and the most efficient group's standard was adopted as the norm. Jobs were reduced to their most basic components by using time and motion studies. The optimal time needed for each task was gauged using stopwatches and each specific operation was listed in instruction cards