Which of the following are. true statements with regard to records retention rules as promulgated under rule 2-06 of regulation S-X

a) review notes that have been cleared (i.e., the question raised has been addressed in the working papers) do not need to be retained

b) a memo evaluating a client's accounting for a particular transaction, and indicating that the auditor was aware of an alternative method of accounting but that the auditor agrees that client's accounting is in conformity with GAAP, should be retained

c) notes take by a person consulted on a significant accounting issue may need to be incorporated into the working papers, but it would be the responsibility of the person consulted to ensure that the notes or their substance are forwarded to the engagement team so that this can be accomplished

d) all of the above