When a CPA knows that a tax client has skimmed cash receipts and not reported the income

Question:

When a CPA knows that a tax client has skimmed cash receipts and not reported the income in the federal income tax return but signs the return as a CPA who prepared the return, the CPA has violated which of the following AICPA rules of conduct?
a. Rule 301— Confidential Client Information.
b. Rule 102— Integrity and Objectivity.
c. Rule 101— Independence.
d. Rule 203— Accounting Principles.