Final answer:
All brokerages are required to keep detailed accounting system records of client funds and other forms, irrespective of their size.
Step-by-step explanation:
The question asks about the requirements for maintaining detailed accounting system records of client funds and other forms by brokerages. The correct answer to this question is d. All brokerages, regardless of size. Every brokerage, no matter how small or large it is, has a legal and ethical obligation to keep detailed records of client funds. This is a standard practice enforced by regulatory bodies to ensure that there is accountability and transparency in the management of client funds.