选择题：[单选题,8.8分] -Dad, I.ve got an "A" in the math exam.

题目内容：
[单选题,8.8分] -Dad, I.ve got an "A" in the math exam.
-Great. And I.m sure you will do better, because this is a good _________.

A.report
B.result
C.start
D.skill
参考答案：