The technology ________, patented by Nikola Tesla, birthed the idea of controlling vehicles remotely.

• A. Radio waves
• B. X-rays
• C. Magnetic fields
• D. Ultraviolet

Answer: (A)

Wireless remote control relies on sending signals through space without wires. Nikola Tesla explored this idea by using radio waves to transmit control signals, filing a patent for a system to control mechanisms remotely and demonstrating a small boat that could be steered without physical connections. This work established the concept of guiding vehicles from a distance, which is the foundation of remote-controlled technology used in drones today. The other options don’t fit because X-rays are for imaging, ultraviolet isn’t tied to practical remote signaling for vehicle control, and magnetic fields don’t describe the wireless signaling method Tesla used to remotely operate a vehicle.