Which of the following is most closely related to the relevance of audit evidence?

a. Auditors decide to physically inspect investment securities held by a custodian instead of obtaining confirmations from the custodian.

b. In addition to confirmations of accounts receivable, auditors perform an analysis of the aging of accounts receivable to evaluate the collectability of accounts receivable.

c. In response to less effective internal control, auditors increase the number of customer accounts receivable confirmations mailed compared to that in the prior year.

d. Because of a large number of transactions occurring near year- end, auditors decide to con-firm a larger number of receivables following year- end instead of during the interim period.