Which of the Following Is the "Signature" Clause of the Sarbanes-Oxley

Which of the following is the "signature" clause of the Sarbanes-Oxley Act?

A) CEOs and CFOs of publicly-traded firms must vouch for the veracity of the firm's financial statements.
B) Corporate board audit and compensation committee members must come from outside directors.
C) Companies may not make loans to their officers and directors.
D) Companies must test their internal financial controls against fraud.