The auditing of joint stock companies shall be carried out both internally and externally. For internal auditing, in addition to the Board of Auditors, the auditing shall be carried out by independent auditing companies (sworn financial accountants such as the big four auditing companies) or alternatively, medium and small size companies may use the services of sworn financial advisors or public accountants.

External audit is performed primarily by the Ministry of Customs and Trade. In additian to these, tax offices also have authority to audit the company accounts.

The correct answer is E.