Under industry rules, which of the following statements describes a discretionary account?

This statement pertains to the pricing structure and commission discounts, which are not related to the discretionary nature of an account. Discounting commissions does not imply that the RR has decision-making authority over trades in the account; thus, it does not define a discretionary account.

Granting power of attorney indicates that a customer can make decisions on behalf of another individual, which is the opposite of a discretionary account. In a discretionary account, the RR is the one with the authority to trade, not the customer.

While this statement suggests some level of discretionary authority, it falls short of defining a full discretionary account because it specifies that the customer provides instructions on the amount of the security. In a true discretionary account, the RR has the authority to make all decisions without such limitations.