单项选择题

执行语句序列

ofstream outfile(“DATE.DAT”);

if(…)cout<<"OK"; else cout<<"FAIL"后,如果文件打开成功,显示“OK”,否则显
示"FAIL"。由此可知,上面if语句…处的表达式是:

A.outfile.fail( )或outfile
B.outfile.good( )或outfile
C.outfile.good( )或!outfile
D.outfile.fail( )或!out file