Giventhefollowingcode，whichmethoddeclarations，wheninsertedattheindicatedposition，willnotcausetheprogramtofailcompilation？（）publicclassQdd1f{publiclongsum（longa，longb）{returna+b；}//insertnewmethoddeclarationhere}
A.publicintsum（inta，intb）{returna+b；}
B.publicintsum（longa，longb）{return0；}
C.abstractintsum（）；
D.privatelongsum（longa，longb）{returna+b；}
E.publiclongsum（longa，intb）{returna+b；}