An object-ownership self-check tests copied reference values, polymorphic dispatch and stable equality contracts.
Review the contracts
Review copied references, method dispatch, equality and hashing before answering.
Choose and explain an answer
Draw the object references first. Then decide which declaration is selected at compilation and which implementation runs at runtime.
Select an answer for every question, then check the result and read each explanation. Progress remains in this browser; this is a self-check, not a judged program submission or a credential.
Common Mistakes
Reassigning a parameter does not reassign the caller's variable. A final reference can still point to mutable state.