Final answer:
The end of the Punic Wars had the greatest impact on the expansion of the economy of the Roman Empire by securing control over territories, expanding the grain supply, obtaining enslaved labor, and absorbing vast trade networks that enhanced commerce.
Step-by-step explanation:
The greatest impact on the expansion of the economy of the Roman Empire would have been A) the end of the Punic Wars. The Punic Wars significantly shaped the Mediterranean region politically and economically. After their conclusion, Rome secured control over vast territories and their resources. It expanded its grain supply by conquering prolific grain-producing regions such as Sicily, Sardinia, and later Egypt. Rome also gained a significant population of enslaved people from these conquests, who were integral to the Roman economy, particularly in agriculture and mining.
Additionally, by absorbing Carthage's trade networks, Rome enjoyed increased trade and wealth which allowed them to fund large-scale public works and military endeavors. The stability Rome provided after the Punic Wars, combined with its large-scale infrastructure projects, facilitated trade and commerce across the Mediterranean, fueling economic growth and prosperity throughout the Empire.