Collin's reagent is [RPMT 2002]

• A. \[MN{{O}_{2}}/HCl\]
• B. \[MN{{O}_{4}}/{{C}_{5}}{{H}_{5}}N\]
• C. \[{{K}_{2}}C{{r}_{2}}{{O}_{7}}/{{H}_{2}}S{{O}_{4}}\]
• D. \[C{{r}_{2}}{{O}_{3}}/2{{C}_{5}}{{H}_{5}}N\]