选择题
2003 AMC 8 Problem 18: Sarah's Party Graph
Each of the twenty dots on the graph represents one of Sarah's classmates. Classmates who are friends are connected with a line segment. For her birthday party, Sarah is inviting all of her friends and all of those classmates who are friends with at least one of her friends. How many classmates will not be invited to Sarah's party?
A.
1
B.
4
C.
5
D.
6
E.
7