Which factor was central to the profound socio-economic impact of Nikola Tesla’s AC electrical system?

💡 Explanation:

The key advantage of alternating current (AC), which Nikola Tesla championed and developed, was the ease with which its voltage could be efficiently 'stepped up' using transformers for long-distance transmission with minimal power loss, and then 'stepped down' for safe consumption. This capability enabled the construction of centralized power plants (like Niagara Falls) that could electrify entire cities and rural areas, fundamentally changing industry and urbanization during the Second Industrial Revolution. This large-scale electrification constitutes the profound socio-economic impact.