Audit reports sometimes include explanatory language that does not result in a "qualified" opinion -- that is the explanatory language can exist alongside a clean "unqualified" opinion.Which of the following is true about audit reports that include explanatory language?

a. During the2000-2009time period,the presence of several kinds of explanatory language was predictive of a lower risk of subsequent restatement of the financial statements.

b. During the2000-2009time period,the use of explanatory language occurred in nearly 90%ofaudit reportsamong USApublic companies.

c. During the2000-2009time period,the use of explanatory language occurred rarely,i.e.,in less than 3%ofaudit reportsamong USApublic companies.

d.During the2000-2009time period,the presence of several kinds of explanatory language was predictive of a higher risk of subsequent restatement of the financial statements.