How Did the Sarbanes-Oxley Act Strengthen Auditor Independence

How did the Sarbanes-Oxley Act strengthen auditor independence?

A) By requiring auditors to provide reports in accordance with the Foreign Corrupt Practices Act.
B) By requiring auditors to report the nature of any auditor-client disagreements to the SEC.
C) By requiring the lead partner to rotate off the audit engagement at least every five years.
D) By requiring a different audit firm from the one that performs the audit to prepare the client's tax return.