Lisa, a member, is a partner in the firm Cohen & Rowen, CPA's. The firm provides a wide variety of services to its clients including appraisal, valuation, and actuarial services. The firm performs attest engagements for a number of clients for which they also provide appraisal, valuation, and actuarial services. Which of the following appraisal, valuation, or actuarial services would impair the firm's independence if performed for an attest client?

• a) A valuation of the client's proposed business combination where the results are not material to the client's financial statements
• b) An appraisal of assets that are not material to the client's financial statements
• c) An actuarial valuation of the client's pension liabilities if those liabilities are material to the client's financial statements.
• d) None of the above