Pick out the endothermic reaction out of the following.
A
C + $$\frac{1}{2}$$O<sub>2</sub> = CO
B
CO + 3H<sub>2</sub> = CH<sub>4</sub> + H<sub>2</sub>O
C
CaCO<sub>3</sub> = CaO + CO<sub>2</sub>
D
CO + $$\frac{1}{2}$$O<sub>2</sub> = CO<sub>2</sub>
Correct Answer: CaCO<sub>3</sub> = CaO + CO<sub>2</sub>