Which of the following actions cause an indirect change to a database table requiring a...

Comprehensive and Detailed Explanation From Exact Extract:

In ABAP Cloud projects, structural changes to persisted artifacts must respect upgrade-safe contracts. Changes that alter the physical layout of a table (removing a column that comes via an included structure, or shortening the length of a column by changing its domain) lead to a database conversion because data type/column layout changes must be reconciled on the DB. While our RAP/CDS guides focus on modeling and service exposure, they emphasize strict, typed modeling and upgrade stability—any structural change that affects persistence is subject to strict checks and lifecycle handling.

By contrast, field labels (texts) do not change the physical table layout and thus don’t require a conversion.