Tag not monitored by Microsoft.
Yep - the wording is misleading. The statement that external-tool users “cannot deploy metadata changes” sounds like the users are fundamentally unable to modify the semantic model, which would suggest that permissions or some other access setting is missing.
What the question actually means is that the external tool cannot currently deploy metadata changes because the XMLA endpoint is not configured for write operations. Once the capacity's XMLA endpoint is set to Read Write, the external tool can deploy those metadata changes.
So the intended interpretation is: “Users of an external tool cannot deploy metadata changes to SalesModel [because the XMLA endpoint is currently read-only]. What should you configure?” The answer is correct, but the wording of “cannot” is unnecessarily ambiguous and can easily lead you toward the workspace-permission answers.
Microsoft staff monitors this forum, so hopefully at some point this will be corrected. Also note that, in general, questions on the actual exam are subject to more scrutiny that practice questions.
If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
hth
Marcin