Once or twice he has had difficulty making decision on his own, but ______  he is an independent man. [ ]

A. in all

B. in word

C. all in all

D. word in word

阅读以下说明和C++代码，将应填入____处的语句或语句成分写在答题纸的对应栏内。

某数据文件students.txt的内容为100名学生的学号和成绩，下面的程序将文件中的数据全部读入对象数组，按分数从高到低进行排序后选出排名前30%的学生。【C++代码】