Read each sentence to find out whether there is any grammatical error in it. The error if any, will be in one part of the sentence. The letter of that part is the answer. If there is no error, the answer is ( e ) (ignore the errors of punctuation, if any.)
Having acquired some experience (a)/ she is no longer (b)/ one of those who believes (c)/ every explanation she is given. (d)/ No error (e).