Which of the following accounts can a brokerage firm NOT open for a customer?

A brokerage firm cannot open an account for a minor directly because minors are generally not legally allowed to enter into contracts, which is a requirement for account opening. Instead, if a minor needs to invest, a custodian account such as a Uniform Transfers to Minors Act (UTMA) or a Uniform Gifts to Minors Act (UGMA) account must be established. In these types of accounts, an adult is designated as the custodian and manages the investment until the minor reaches the legal age.

In contrast, pension funds, insurance companies, and estates are all legitimate entities or structures that can legally enter into contracts and therefore can have brokerage accounts opened for them. Pension funds are established to manage retirement funds, insurance companies deal with various types of insurance and related investment activities, and estates handle the assets of deceased individuals, all of which can function within the financial system as account holders.