Which of the following an example of a document that is Not required to be retained under Rule 2-06 of regulation s-x?

a) A result of audit tests that yield unsatisfactory results, but are not currently included within the working papers

B) An e-mail including judgement as to the appropriateness of the client estimate of the allowance for doubtful accounts, which has also been transcribed with in the accounts receivable working papers

c) an e-mail that duplicates a conclusion contained within the working papers, but that also includes additional analyses utilized in reaching that conlcusionnot documented elsewhere

d)all of the above