Choice "B" is correct. The auditor's report should include reference to the United States as the country of origin of both the accounting principles used to prepare the financial statements and the auditing standards the auditor followed in performing the audit.
Choice "a" is incorrect, since the auditor's report should include reference to the country of origin of the auditing standards the auditor followed in performing the audit.
Choice "c" is incorrect, since the auditor's report should include reference to the country of origin of the accounting principles used to prepare the financial statements.
Choice "d" is incorrect, since the auditor's report should include reference to the country of origin of both the accounting principles used to prepare the financial statements and the auditing standards the auditor followed in performing the audit.