Identify the error in the following sentence: (a) The accusation of abatement to the crime (b) that had been levelled at him (c) was eventually not proven in court. (d) No error.

The error lies in part (a). The word 'abatement' means a reduction or lessening (as in 'abatement of nuisance'). The correct legal term required here is 'abetment', which means the action of encouraging or assisting in a crime. The phrase should be 'the accusation of abetment to the crime'. This is a classic confusing pair, and the substitution of 'abatement' for 'abetment' constitutes the error. Parts (b) and (c) are grammatically and idiomatically correct.