单项选择题

When the adjacency matrix method is used to store a graph, which of the statements is (are) true ( ) Ⅰ.the space required depends on the number of vertices Ⅱ.the apace required depends on the number of edges

A.None
B.Ⅰ only
C.Ⅱ only
D.Ⅰ and Ⅱ