Which scenario leads to a successful build of a copied design-time file?

The scenario leading to a successful build of a copied design-time file is characterized by the condition of the source design-time file. A source design-time file that has never been built ensures that there are no prior build-related errors or issues that could complicate the copying process. In this case, since the file is untouched and exists solely in its original, unbuilt state, it can be copied and subsequently built without any complications arising from previous versions or builds.

A design-time file that has been regularly updated might introduce variability or unresolved dependencies, which could hinder the copy and its eventual build. If the source file has never been built, there are also no alterations or errors left unresolved that could affect the copy's integrity. In contrast, deleting the source file before copying it introduces ambiguity and potential failure, as the foundational file required for the build does not exist anymore.

Therefore, having a source design-time file that has never been built is the most favorable condition for successful copying and building, as it represents a clean slate free from prior complications.