Which of the following is NOT an exception to the rule prohibiting business transactions with clients?

The choice indicating that large transactions without documentation are not an exception to the rule prohibiting business transactions with clients is accurate. In the context of professional responsibility, particularly concerning the attorney-client relationship, the rules aim to prevent conflicts of interest and protect clients from potential exploitation.

The basic principle is that lawyers must act in their clients' best interests and maintain professionalism. Ordinary transactions, especially those that are typical and reasonable within the context of the attorney-client relationship, can indeed be seen as exceptions provided they meet specific conditions like fairness and transparency. Similarly, transactions that are fair and include appropriate disclosures can also be exceptions, assuming all necessary conditions are satisfied.

However, large transactions without documentation do not fall under any permissible exception. Such transactions lack transparency and could result in significant conflicts of interest or misconceptions about the nature of the transaction, thereby undermining the trust fundamental to the attorney-client relationship. Counsel must ensure that any business dealings with clients are documented, fair, and conducted with full disclosure to uphold the ethical standards expected in legal practice.