Final answer:
The true appeal of promoting electricity for Morgan likely encompasses profit potential, as it supports many facets such as helping industries, advancing national defense, and being driven by technological innovation.
Step-by-step explanation:
For Morgan, the true appeal of promoting electricity was not solely based on one aspect of its use. Given the context provided, the options include environmental benefits, technological innovation, profit potential, and national security. While all these factors are important, the reference to diversified energy sources increasing economic opportunity, the emphasis on employment opportunities in renewable energy, and the impact on national defense through energy security suggest that Morgan's interest in promoting electricity could be aligned with profit potential and strengthening industries, which in turn potentially help workers and advance national defense.
Given the historical advancements in electrical power like Westinghouse's alternating current, it's likely that technological innovation was also a significant appeal to Morgan. This not only supported profit potential but also the advancement of national defense through increased resilience in the face of disruptions. Thus, the most encompassing option seems to be profit potential, which indirectly incorporates helping industries stay strong and advancing national defense.