In the following question, one part of the sentence may have an error. Find out which part of the sentence has an error. If the sentence is free from error, click the ‘No Error’ option.

While the excise duty is fixed per litre (A)/ of petrol, VAT(or sales tax, as it (B)/ is referred in to some states) at the state (C)/ government level works on an ad-valorem basis. (D)