List two of the first AC systems.

When considering the early development of alternating current (AC) systems, the correct answer points to two significant systems: Gold King Mine and Willamette Falls. These locations were instrumental in the practical application of AC power systems shortly after their development.

Gold King Mine was among the first to adopt AC technology to efficiently power mining operations, showcasing the utility of AC for industrial applications. Similarly, Willamette Falls was one of the early sites where AC was applied for generating and distributing electricity, taking advantage of the hydroelectric potential of the falls. Both locations exemplified innovative uses of AC systems during a pivotal time in electrical engineering history.

The other options represent cities and power stations that, while significant in the broader context of electrical power distribution, are not recognized as foundational in the implementation and early usage of AC as a primary source of electrical energy. Thus, the selection of Gold King Mine and Willamette Falls accurately reflects the early advancements in AC technology.