Final answer:
Both technicians are correct: drain and fill plugs can be found on oil pans and transmissions, and they are indeed a type of threaded plug.
Step-by-step explanation:
Both Technician A and Technician B are correct in the context of this question. Technician A states that drain and fill plugs are located on oil pans and transmissions. This is true because these plugs are used to drain and then refill with oil or transmission fluid. Technician B states that drain and fill plugs are a type of threaded plug. This is an accurate description, as these plugs are inserted into the pan or transmission with threads that allow them to be screwed in and out to control the flow of fluid.