Past exam of the year 1 of the computer science course of the University of Oxford / 2023 / Imperative programming / 6 / b / v / Solution

Permitted; returns "BC". The receiver's static type is C, but the argument's static type is only B. Thus show(C) is inapplicable; among show(A) and show(B), the latter is more specific. Its implementation is C.show(B), whose superclass call returns "B" before "C" is appended. The argument happens to reference a C object, but method overloading uses its static type.