From a design perspective which two of the following OHPF Statements are most relevant？（）

• A、 OSPF stub areas can be thought of as a simple form of summarization
• B、 OSPF cannot filter intra area routes
• C、 An ARR ran only exist in two areas - the backbone and one adjacent area
• D、 Performance issues in the Backbone area can be offset by allowing some traffic to transit anon-backbone area
• E、 the size of an area （the LSDB） will be constrained by the size of the IP MTU