Which of the following can be used as both a risk assessment procedure and a substantive procedure for the audit of accounting estimates?

a. Gain an understanding of what is required by the applicable financial reporting framework.

b. Inquire of management about the methods and assumptions used in developing the estimate.

c. Inspect documentation for proper approval of the accounting estimate.

d. Inspect events happening after year-end and up to the date of the auditor’s report.