You create Web sites for your company. You apply a consistent design to the pages and controls of the Web sites. You need to make style changes to all of the Web sites on the Web server. You want to achieve this goal without having to edit the individual pages on each Web site. Which two actions should you perform?（）

A. Place a theme in the App_Themes directory under the application root directory.
B. Place a theme under an ASNETClientFiles folder under the ASNET installation directory.
C. Assign a theme by setting the directive to the name of the application theme.
D. Assign a theme by specifying the section in the Web.config file.