Under CC BY, which requirement is mandatory?

• A. You must attribute the creator and provide a link to the license.
• B. You must restrict usage to non-commercial purposes only.
• C. You must obtain explicit permission for any derivative works.
• D. You must place the work in the public domain.

Answer: (A)

Under CC BY, giving credit to the creator and linking to the license is mandatory. This license centers on attribution: you may use, share, or adapt the work as long as you credit the author, provide a link to the CC BY license, and note if you changed anything. The other options don’t fit because CC BY does not require non-commercial use; derivatives are allowed without asking for explicit permission; and it isn’t a way to place the work in the public domain. If you reuse it, include the author, a title if possible, a link to the license, and mention any changes you made.