About Question enthuware.ocpjp.v11.2.3145 :

[dvc1190]

There is no option that would meet the requirement that Phone supports only the call operation and TV supports only the listenOn operation. The "correct" answers result in Phone and TV also supporting connect, disconnect, and setName. In addition, if Phone, TV, and WalkieTalkie are in the same package, they can all change number and frequency if coded to do so.

[admin]

Will make it clear that the requirements are only about call and listenOn methods, while the other methods are common to all.
Thank you for your feedback!