Read each sentence carefully to find out whether there is any grammatical or idiomatic error in it. The error, if any, will be in one part of the sentence marked (a), (b), (c) or (d).If the sentence is correct as it is, choose “No error ” as option (e) your answer. Ignore errors of punctuation, if any. The director spoke with such authority and clarity during the briefing (a) that even those initially sceptical of the proposal (b) was persuaded to reconsider their position (c) by the strength of the argument presented (d). No error (e)