The PCAOB main responsibilities include the following, except:

(a) Registration of accounting firms (including non-US firms) that audit public companies (including non-US issuers) trading in US securities markets

(b) Inspections of registered public accounting firms

(c) Providing a letter grade to public accounting firms

(d) Establishment of auditing and related attestation, quality control, ethics, and independence standards for registered public accounting firms

(e) Investigation and discipline of registered public accounting firms and their associated persons for violations of specified laws or professional standards