以下程序运行时，如果从键盘上输入I am a student↙，则程序的输出结果是(  )
　 #include  
void fun(char c[])
        {
            int i=0;    
     while(c[i])
    {
                if(c[i]>='a'&&c[i]<='z')          
                        c[i]=c[i]-('a'-'A');            
i++;
            }
        }
        void main()
       {    
            char s[81];
    gets(s); 
    fun(s); 
    puts(s);
        }

A． i am a student
B． I AM A STUDENT
C． I Am A Student
D． i Am a Student