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

Permitted; returns "C". Both receiver and argument have static type C, so the most-specific applicable overload is show(C). That method is defined in C and returns its own one-letter result without calling super. The six results, in source order, are therefore AB, AB, AB, BC, BC, C.