A.
mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold" xml:lang="EN-US">void fun(int, int=0);
B.
mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold" xml:lang="EN-US">double fun(x, y);
C.
mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold" xml:lang="EN-US">void fun(*, &);
D.
mso-ansi-language:EN-US;mso-fareast-language:ZH-CN;mso-bidi-language:AR-SA; mso-bidi-font-weight:bold" xml:lang="EN-US">int fun(int =0, int);