单项选择题

现有:1.classOver{2.intdolt(longx){return3;}3.}4.5.classUnderextendsOver{6.//insertcodehere7.}和四个方法:shortdolt(inty){return4;}intdolt(longXrlongy){return4;}privateintdolt(shorty){return4;}protectedintdolt(longx){return4;}分别插入到第6行,有几个可以通过编译?()
A.1
B.2
C.3
D.4

A.classOver{2.intdolt(longx){return3;}3.}4.5.classUnderextendsOver{6.//insertcodehere7.}和四个方法:shortdolt(inty){return4;}intdolt(longXrlongy){return4;}privateintdolt(shorty){return4;}protectedintdolt(longx){return4;}分别插入到第6行,有几个可以通过编译?()
A.1
B.2
C.3
D.4