Auditor X, a CPA, is performing an attestation review engagement. The subject matter is a production report of Y Company representing the total production of its 12 products for the prior year. Corporation A has engaged X to provide assurance on the production report to determine whether an acquisition of Y is appropriate. Based on these facts, which of the following statements made about the assertion is true?

a. The assertion should be in writing.

b. The assertion must be made by the engaging party.

c. If no assertion is presented, the practitioner need not disclose the omission in the report.

d. The assertion should cover the financial statements for the same period.