The correct option is C CH3Br+AgF⟶CH3F+AgBr
Alkyl fluorides are prepared by the action of heavy metallic (mercurous or antimony) fluorides on corresponding alkyl chloride or bromide and is called Swartz reaction.
CH3Br+AgF→CH3F+AgBr
Reaction (a) and (b) is Finkelstein reaction.
Reaaction (d) is Wurtz reaction.
Thus, option (c) is correct.