8. When crude oil is pumped through the furnace the first heat transfer to the tubes occurs when the hot flue gases rise and heat the tubes. The oil tubes are heated first by the process of
A. condensation
B. radiation
C. convection
D. conduction
8. When crude oil is pumped through the furnace the first heat transfer to the tubes occurs when the hot flue gases rise and heat the tubes. The oil tubes are heated first by the process of
A. condensation
B. radiation
C. convection
D. conduction