Which of these reactions are exothermic? 1. $\text{C} + \text{O}_2 \rightarrow \text{CO}_2$ 2. $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$ 3. $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$
- A1, 2 and 3
- B1 and 2 only
- C1 and 3 only
- D2 and 3 only