26. Which of the following is not one of the principal CPA firm's options when issuing a report for which another CPA firm performed part of the audit? a. An unqualified opinion is required if the principal CPA firm is not willing to assume any responsibility for the work of the other CPA firm. b. A standard unqualified report and make no reference to the other CPA firm in the report. c. A qualified opinion or adverse opinion, depending on materiality, is required if the principal CPA firm is (a) not willing to assume responsibility for the work of the other CPA firm, (b) unable to be satisfied as to the professional reputation of the other CPA firm, and (c) unable to satisfied as to the independence of the other CPA firm. d. A standard unqualified report if the principal CPA firm has thoroughly reviewed the other CPA firm's work