Product Backlog Refinement details

The description of refinement was changed between the 2017 and 2020 versions of the Scrum Guide.

In the 2017 edition of the Scrum Guide, Product Backlog Refinement was described as:

Product Backlog refinement is the act of adding detail, estimates, and order to items in the Product Backlog. This is an ongoing process in which the Product Owner and the Development Team collaborate on the details of Product Backlog items.

In the 2020 edition, the description was changed to:

Product Backlog refinement is the act of breaking down and further defining Product Backlog items into smaller more precise items. This is an ongoing activity to add details, such as a description, order, and size. Attributes often vary with the domain of work.

The idea of decomposing the work into smaller and more precise items with additional details remains, the exact details that are added are now left as something to be determined by the Scrum Team. In addition, the word "estimate" was entirely removed from the Scrum Guide in the 2020 revision.

My recommendation is that if the team is estimating and sees value in estimating, then that would be part of Product Backlog Refinement. However, estimation is not required and some teams may not see the value in doing so. As long as each Product Backlog Item can be completed by the team within a Sprint, Scrum doesn't call for any particular attributes or activities as part of refinement.

This is an ongoing activity to add detail such as..

1. Description    2. Estimation    3. Order    4. Size    5. Risk

Depending on context, all of these exemplify the kind of detail that might be added.

As @Thomas Owens pointed out, the textbook answer is what they site indicated.  But as both @Thomas Owens and @Ian Mitchell indicate, all of those items could be useful to specific teams and there is no reason that they shouldn't provide them as part of refinement.  Notice these words the quote Thomas provided from the current revision of the Scrum Guide

...such as a...

Attributes often vary with the domain of work.

There is not right answer. Once again, the Scrum Guide suggests some attributes that have been found to help but it is not prescriptive on what attributes have to be included.  So, to correctly answer the question on the quiz, select 1, 3, and 4.  To correctly answer the question in practice, ask the team what attributes they feel are needed in order for a Product Backlog Item to be fully understood and ready for inclusion in a Sprint Backlog.