This is called a complex reaction time. Since the response is for a multiple stimuli and response possibilities, it should be a complex one which relates to "many" or multiple. The total time to respond to a stimuli is called a reaction time. Thus, it represents a complex reaction time.
The world population DOUBLED. Thanks Industrial Revolution. Thomas Edison brought the world to light at night! Massive factories drew millions to cities–and people were able to ride there on new steam locomotives.
