The Balkan Sprachbund, also known as the Balkan linguistic area, refers to a group of languages in the Balkan region that share common features due to prolonged contact and influence, rather than genetic relatedness. Some of the key features of this Sprachbund include the loss of the infinitive, the use of the subjunctive in specific contexts, and specific vowel and consonant shifts.
- Romanian and Bulgarian are both part of the Balkan Sprachbund because they exhibit these common linguistic features. Romanian, a Romance language, and Bulgarian, a Slavic language, both share these syntactic and morphological characteristics due to historical contact in the region.
- Norwegian and Swedish, however, are Germanic languages and are not part of the Balkan Sprachbund. They do not exhibit the same linguistic features shared by the Balkan languages.
Thus, the correct answer is (A) Romanian, (B) Bulgarian.