Is CC-BY 4.0 attribution recursive?

Question

Let's say we have Work A licensed under CC-BY 4.0, made by Author A.

Author B uses Work A to create Work B, attributing Work A: "Work A was created by Author A under the CC-BY 4.0 license (link to work A here). Work B is also under the CC-BY 4.0 license."

Now Author C comes along and wants to use Work B to create Work C. Do they need to attribute Author A as well as Author B? Or do they only need to attribute Author B?

Option 1, non-recursive: "Work B was created by Author B under the CC-BY 4.0 license (link to work B here). Work C is also under the CC-BY 4.0 license."

Option 2, recursive: "Work A was created by Author A under the CC-BY 4.0 license (link to work A here). Work B was created by Author B under the CC-BY 4.0 license (link to work B here). Work C is also under the CC-BY 4.0 license."

My own research

This is the relevant legal code:

Attribution.

    If You Share the Licensed Material (including in modified form), You must:
        retain the following if it is supplied by the Licensor with the Licensed Material:
            identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);
            a copyright notice;
            a notice that refers to this Public License;
            a notice that refers to the disclaimer of warranties;
            a URI or hyperlink to the Licensed Material to the extent reasonably practicable;
        indicate if You modified the Licensed Material and retain an indication of any previous modifications; and
        indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

In particular, "identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor".

Who are "any others designated to receive attribution"? What if the Licensor does not request anything other than licensing their work under CC-BY 4.0?

Answer 1

I assume that by "Author B uses Work A to create Work B" you mean that Author B makes work B which is a copyright derivative of work A. Work C, then, is then a copyright derivative of both works B and A. Authors A, B, and C are rightsholders in this work, and C will be violating A and B's copyrights if (s)he distributes this work without a licence to do so from both A and B.

Fortunately, A and B have both granted such a licence, by publishing their works under CC BY 4.0, provided C attributes them both as described above.