@Nora, CPA and Ocean: C is correct!
Explanation:
A review is substantially less in scope than an audit. It involves applying inquiry and analytical procedures to obtain a basis for providing limited assurance that there are no material modifications that should be made to the financial statements for them to be in conformity with generally accepted accounting principles.
Unlike an audit, a review does not involve obtaining an understanding of internal control, assessing control risk, assessing fraud risks, testing of accounting records, obtaining corroborating evidence (such as confirmations), or expressing an opinion on the financial statements taken as a whole.
The accountant should establish an understanding with the client, preferably in writing, prior to a review. However, the standards do not mandate that an engagement letter be used for this purpose.