Which of the following assets in an account must a broker-dealer maintain physical possession or...

Broker-dealers are subject to customer protection requirements that include the obligation to maintain physical possession or control of certain customer securities. Specifically, firms generally must maintain possession or control of fully paid-for securities and excess margin securities (unless an exemption applies). That is why D is correct. The concept is investor protection: ensuring that customer securities are safeguarded and readily available, rather than being improperly used by the firm or exposed to unnecessary risk.

“Fully paid-for” securities are securities that a customer has paid for in full and therefore should not be encumbered by the firm. “Excess margin” securities are those with a market value greater than what is necessary to support the customer’s margin debit. Because these securities represent customer property beyond what is needed as collateral, regulators require heightened safeguards—possession or control—so the firm cannot freely rehypothecate or otherwise misuse them beyond permitted limits.

Choice A is too broad; while many securities are protected, not all securities in an account fall under the same possession-or-control requirement in the same way, especially when margin collateral rules allow certain use within limits. Choice B is nonsensical because “the entire brokerage account” is not an asset and cannot be physically possessed. Choice C is incomplete because it ignores the “excess margin securities” component, which is explicitly included in the standard phrasing of this requirement.

For SIE purposes, this is tested as part of custody/safeguarding rules, customer protection concepts, and firm obligations relating to holding customer assets.