Which two are true regarding a web application class loader？（）

A.A web application may override the web container’s implementation classes.
B.A web application running in a J2EE product may override classes in the javax.* namespace.
C.A web application class loader may NOT override any classes in the java.* and javax.* namespaces.
D.Resources in the WAR class directory or in any of the JAR files within the library directory may be accessed using the J2SE semantics of getResource.