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

Permitted; returns "AB". Through a receiver of static type A, only show(A) is visible. The argument's static type C is a subtype of A, so it can be passed to that method. Dynamic dispatch selects B.show(A) on the receiver object, exactly as in part (i). The argument's more specific type cannot expose overloads absent from the receiver's static type.