Technician A says that the piston's most important function is to transfer the force produced by the burning air-and-fuel mixture into usable power. Technician B says that the piston size is used to help form a seal between the piston and the cylinder walls. Who is right?

A. Technician B only
B. Technician A only
C. Both Technicians A and B
D. Neither Technician A nor B