Final answer:
The Apennines are the mountain range that runs down the center of the Italian peninsula, distinguishing it from the Alps, which are in the northern part of Italy, and the Pyrenees and Carpathians, which are in other parts of Europe.
Step-by-step explanation:
The mountain range that runs down the center of the Italian peninsula, splitting it into east and west, is c) The Apennines. The Apennines are foundational to the geographic character of Italy, defining much of its landscape and acting as a natural backbone for the country. Unlike the Alps, which stretch across northern Italy and enter into other countries, the Apennines exclusively traverse the Italian peninsula. Further north, the Pyrenees create a natural barrier between France and Spain but are not part of Italy. The Carpathians are located in Eastern Europe and loop mainly through countries such as Romania and Slovakia, which are distant from Italy.