Heat would best be transferred by conduction between A. a candle and the air
B. an oven and a glass dish
C. a stove and a copper pot
D. water and a wooden spoon

Stove and copper pot. The candle and air transfer heat through convection, the oven cannot properly conduct heat to the glass dish, wooden spoon is a horrible conductor in any form, and the copper pot is metal so it can better conduct with the stove

Exothermic,  physical change after it is already baked