多项选择题
Given: Which three are valid?()
A.p0 = p1; B.p1 = p2; C.p2 = p4; D.p2 = (ClassC)p1; E.p1 = (ClassB)p3; F.p2 = (ClassC)p4;
A.Canada B.null Canada C.Canada null D.Canada Canada E.Compilation fails due to an error on line 26. F.Compilation fails due to an error on line 29.
A.three B.other C.An exception is thrown at runtime. D.Compilation fails because of an error on line 12. E.Compilation fails because of an error on line 13. F.Compilation fails because of an error on line 15.