The term 'anchimeric assistance' means

Aincrease in rate caused by a bulky leaving group
Bacceleration of an SN2 reaction by a polar aprotic solvent
Cparticipation of a neighbouring group in the ionisation step, usually raising the reaction rate
Dstabilisation of a carbocation by an external nucleophile

Answer: C

Anchimeric assistance is another name for neighbouring group participation: a group with a lone pair or

π

electrons, located near the reaction centre, displaces the leaving group intramolecularly and so speeds up the reaction.