All of the following choices adhere to the nasaa model rule on unethical business practices of investment advisers and federal covered advisers except when an investment adviser: [a] decides to borrow funds with a promissory note in writing from a client, who is also a controlling shareholder.[b] decides to borrow funds with a promissory note in writing from an institutional lending facility, who also happens to be a client.[c] decides to borrow funds with a promissory note in writing from an individual client.[d] decides to borrow funds through a margin account from a broker-dealer who also just happens to be a client.