Which of the following actions affects the independence of a CPA firm negatively?

The action that negatively affects the independence of a CPA firm is when a partner receives a loan from a client. This is problematic because it creates a conflict of interest and might influence the CPA’s impartiality when conducting audits or providing assurances regarding the client's financial statements. Independence is a cornerstone of ethical practice in accounting; when a financial obligation exists between a CPA and a client, it can cast doubt on the CPA’s ability to remain objective. Accepting loans can lead to the perception that the CPA's professional judgment may be compromised, undermining the integrity expected in performing audits or reviews.

Additionally, maintaining independence requires not only objectivity in thought and judgment but also the appearance of independence in the eyes of users of financial statements. The loan from a client can impair that appearance, making it essential for CPAs to avoid such relationships to uphold ethical standards.

The other scenarios listed may present less direct threats to independence, depending on the specifics, but any financial dealings with a client, like accepting a loan, significantly jeopardize the CPA's duty to remain free from influences that might affect their work.