In the last paragraph, the word "scrapped" can be best replaced by______.

A．Only small countries adopt the unitary system.
B．Unitary states all have uniform culture.
C．Multinational states can be unitary states.
D．The federal system is more suitable for communist states.

A．the revival of some North American and European CBDs
B．the problems facing the development of U.S. downtown areas
C．the moving pattern of the U.S. middle class
D．the possible solutions to the fiscal problems