单项选择题

以下程序的输出结果是
chsr cchar(char ch)
if(ch>=’A’&&ch<=’Z’)ch=ch-’A’+’a’;
return ch;
main()
char s[]=“ABC+abc=defDEF”,*p=s;
while(*p)
*p=cchar(*p);
p++;

printf(“%s\n”,s);

A.abd+ABC=DEFdef
B.abc+abc=defdef
C.abcABCDEFdef
D.abcabcdefdef