Final answer:
Lithuania is the southernmost Baltic State, bordered by the Kaliningrad Oblast of Russia to the west.
Step-by-step explanation:
The country that is the southernmost of the Baltic States and is bordered by the Kaliningrad Oblast portion of Russia to the west is Lithuania. Lithuania, alongside Latvia and Estonia, are collectively known as the Baltic states.
After regaining their independence following the collapse of the Soviet Union in 1991, these countries shifted their focus towards integrating economically and politically with Western Europe.
Lithuania is positioned south of Latvia and Estonia, making it the southernmost Baltic nation. It shares borders with Latvia to the north, Belarus to the east and south, Poland to the south, and the Russian exclave of the Kaliningrad Oblast to the southwest.