单项选择题 During OSPF adjacency formation, in which state is a router in when it is negotiating to be in charge of the database synchronization process?（）

单项选择题 During OSPF adjacency formation, in which state is a router when it is sending LSA header information to its neighbor?（）

单项选择题 Which statement is true about the frequency of OSPF LSA transmissions?（）