In the given reactions, identify the reagent A and reagent B.
A – \( \text{CrO}_2\text{Cl}_2 \) B – \( \text{CrO}_3 \)
A – \( \text{CrO}_3 \) B – \( \text{CrO}_3 \)
A – \( \text{CrO}_2\text{Cl}_2 \) B – \( \text{CrO}_2\text{Cl}_2 \)
A – \( \text{CrO}_3 \) B – \( \text{CrO}_2\text{Cl}_2 \)