What Is the Defining Characteristic of the Dual Banking System

What is the defining characteristic of the dual banking system?

A) Coexistence of parent and holding companies.
B) Coexistence of both nationally chartered and state chartered banks.
C) Control of nationally chartered and state chartered banks by the state regulators.
D) Control of nationally chartered banks by both FRS and State bank regulators.
E) Nonbanking companies carrying out both banking and other activities.