Final answer:
Muller argues that Roman expansion ultimately hurt the Roman Empire, bringing about societal disadvantages, increased reliance on slavery which stagnated innovation, and economic strain due to continuous military conflict.
Step-by-step explanation:
Based on Muller's argument about Roman expansion, it seems most appropriate to infer that he posits Roman expansionism ultimately hurt the Roman Empire (choice A). The text highlights various societal disadvantages such as the loss of life, disruption of critical trade markets like grain which led to famine and riots, and the overall decline of Rome as a result of 'immoderate greatness'. It mentions the burden shouldered by the lower classes and the undermining of the Roman productivity and social status of free citizens due to the reliance on slavery. It also speaks of the internal issues brought about by continuous military conflict and the economic strain of maintaining a vast empire.
Roman expansion contributed to economic growth initially by securing resources and wealth from conquered regions, supporting such needs as feeding the populace and paying the troops. However, Muller elaborates on the detrimental long-term effects of expansion and conquest, such as the undermining effects of slavery on innovation and productivity, increased social inequality, and the unsustainable military expenditures that necessitated further conquest, thus contributing to Rome's eventual decline rather than solely fueling economic growth.