The correct match is A-III, B-I, C-II. Sandmeyer reaction is a reaction used to synthesis aryl halides from aryl diazonium salt.
Finkelstien reaction is a halogen ( X ) exchange method. It is used to prepare alkyl iodide by reaction of alkyl chlorides/bromides with NaI in dry acetone. ‌
R−X
(x=Cl,Br)
+NaI
‌ Acetone ‌
‌───────▶‌
RI+NaX Swartz reaction is used to get alkyl fluorides from alkyl chlorides. R−Br+AgF→R−F+AgBr
