Correct Option (b):
The Adriatic Sea is an arm of the Mediterranean Sea, situated between the eastern coast of Italy and the western coast of the Balkan Peninsula. The countries bordering the Adriatic Sea include:
- Albania: It possesses a significant western coastline along the Adriatic Sea.
- Bosnia and Herzegovina: It has a narrow coastal strip, specifically the Neum corridor, which provides its only access to the Adriatic Sea.
- Croatia: It features an extensive and well-defined Adriatic coastline, encompassing numerous islands and a long mainland stretch.
Therefore, Albania, Bosnia and Herzegovina, and Croatia have the Adriatic Sea as a boundary.
Incorrect Options:
- Macedonia (now officially North Macedonia) is a landlocked country located in the central Balkan Peninsula. It does not have any direct access to the sea, including the Adriatic Sea.
- Options that include Macedonia (1, 2 and 4; 1, 2, 3 and 4) are incorrect due to its landlocked status.
- Option (c) 2 and 3 is incomplete as Albania (1) also shares a boundary with the Adriatic Sea.