The correct answer is: A. Thesis writing.
A certificate for copyright waiver is a document that allows someone to use copyrighted material without permission from the copyright holder. This is often done in the context of thesis writing, where students may need to use copyrighted material in their research. The certificate typically states that the copyright holder is waiving their rights to the material, and that the student is free to use it in their thesis.
A paper is a shorter piece of writing that is typically published in a journal or magazine. Articles are similar to papers, but they are typically longer and more in-depth. Books are longer pieces of writing that are typically published by a publisher.
In all of these cases, the copyright holder may choose to waive their rights to the material. However, this is most commonly done in the context of thesis writing. This is because thesis writing is a significant piece of work that is often published in a scholarly journal. As such, it is important to ensure that the copyright holder is aware of the use of their material and that they are comfortable with it.
If you are unsure whether or not you need a certificate for copyright waiver, it is always best to err on the side of caution and contact the copyright holder. They will be able to advise you on the best course of action.