OSPF uses SPF algorithm to calculate SPF tree according to topology. Which of the following statements are correct regarding SPF tree node? (Choose two.)
A. The node on SPF tree indicates router and port.
B. There are two types of SPF tree nodeTransit node and Stub node.
C. The router node on SPF tree is one type of Stub nodes.
D. The router node on SPF tree is one type of Transit nodes.