Read this: ^7 A census category recognized as an ethnic group. Most Slavic Muslims (especially in Bosnia, Croatia, Montenegro and Serbia) now opt for Bosniak ethnicity, but some still use the "Muslim" designation. Bosniak and Muslim are considered two ethnonyms for a single ethnicity and the terms may even be used interchangeably. However, a small number of people within Bosnia and Herzegovina declare themselves Bosniak but are not necessarily Muslim by faith.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Which areas tend to use the Muslim designation?
unanswerable