A.XBXB、XbY B.XBXb、XBY C.XbXb、XBY D.XBXb、XbY
A.1/4,1/2 B.1/2,1/2 C.1/2,1/4 D.1/4,0
A.全部 B.1/2 C.1/4 D.0