Final answer:
One way to recognize whether an online source has been copyrighted is if it features the phrase "all rights reserved."
Step-by-step explanation:
An online source can be recognized as copyrighted if it features the phrase "all rights reserved." This phrase indicates that the content is protected by copyright laws and cannot be used without permission. It is a common way for creators to assert their ownership over the material.
Learn more about Copyrighted online sources