Which of the following statements is correct concerning both an engagement to compile and an engagement to review a non-public entity’s financial statements?

Which of the following statements is correct concerning both an engagement to compile and an engagement to review a non-public entity’s financial statements?
a. The accountant is not required to obtain an understanding of internal control.
b. The accountant must be independent in fact and appearance.
c. The accountant expresses no assurance on the financial statements.
d. The accountant should obtain a written management representation letter.