Technician A says that the burning of the air-and-fuel mixture in the cylinder is called fuel activation. Technician B says that the basic function of the upper-end components is to control the flow of air-and-fuel mixture into the engine and the flow of exhaust gases out of the engine after combustion. Who is right? A. Both Technicians A and B B. Technician A only C. Neither Technician A nor B D. Technician B only