Which of the following is a reason that the auditor obtains an understanding of the client’s internal control over financial reporting?

a. This understanding is required by professional auditing standards. 

b. Understanding of internal control is needed to properly plan the audit. 

c. This understanding helps an auditor assess a client’s risk of material misstatement.

d. All of the above are reasons why the auditor obtains an understanding of the client’s internal control over financial reporting.