关于LSA描述正确的是：
A
LS type,LS sequence number和Advertising Router的组合共同标识一条LSA
B
LS type,Link State ID和Advertising Router的组合共同标识一条LSA
C
LS type,Link State ID和LS sequence number的组合共同标识一条LSA
D
LS sequence number,Link State ID和Advertising Router的组合共同标识一条LSA