The following equations represent two reactions. reaction X: $2\text{NOBr} \rightarrow 2\text{NO} + \text{Br}_2$ reaction Y: $2\text{NOCl} \rightarrow 2\text{NO} + \text{Cl}_2$ These two reactions proceed by similar mechanisms. When temperature, pressure and reactant concentration are all the same, the starting rate of reaction X is higher than the starting rate of reaction Y. Which statements account for this difference?
- A1 and 2
- B2 and 3
- C1 only
- D3 only