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.

The virulent invader, who swept through Asia and (A)/ Europe, is leading many U.S. businesses to hoard cash, limit (B)/ spending and rethink how they operate without (C)/ knowingly how long the troubles will last.(D)