Final answer:
George Westinghouse invested in Tesla's idea of alternating current (AC) electricity, which led to widespread adoption of AC power across the United States.
Step-by-step explanation:
The correct answer is b) J.P. Morgan. J.P. Morgan was a prominent American businessman and financier who invested in Tesla's idea. Morgan is known for his role in financing the consolidation of industry and negotiation of leading corporations such as General Electric and US Steel.
The person who finally invested in Nikola Tesla's idea was George Westinghouse. In the late 19th century, Tesla pitched the merits of alternating current (AC) electricity over direct current (DC), which was promoted by Thomas Edison. Despite a public relations battle against Edison, Westinghouse saw the potential in Tesla's AC system and its ability to transmit electricity over long distances, which was a significant advantage over Edison's DC system.
Westinghouse Electric Company, founded in 1886, played a pivotal role in adopting AC power and profoundly impacted the electrical infrastructure in the United States.