Final answer:
The line of volcanic peaks is most likely created by tectonic and volcanic forces, resulting from the cracking of the Earth's crust and the splitting of older craters. Extensive mountain ranges and volcanic activity contribute to the formation of these peaks.
Step-by-step explanation:
The line of volcanic peaks, where the volcanoes are progressively older toward one end of the line, is most likely created by tectonic and volcanic forces. This phenomenon is often observed in areas where the Earth's crust cracks and older craters are split and pulled apart. The formation of extensive mountain ranges from the compression of the crust also contributes to the creation of such volcanic peaks. Examples of regions with similar volcanic activity include the western margin of South America and the Hawaiian island chain.