Which of the following frequencies can dual-band routers transmit Wi-Fi signals in?

Dual-band routers are designed to operate on two frequency bands that are standard for Wi-Fi communications, specifically 2.4 GHz and 5 GHz. The 2.4 GHz band is commonly used for longer range and better penetration through obstacles, making it suitable for general use and devices that don't require high speeds. On the other hand, the 5 GHz band offers greater bandwidth and faster data rates, ideal for high-performance applications like gaming and video streaming.

The other frequency pairs listed do not align with the recognized bands for dual-band routers. Frequencies like 1.2 GHz, 3.4 GHz, and combinations like 2.0 GHz and 4.5 GHz are not part of the standard Wi-Fi frequency spectrum, making them unsuitable for typical Wi-Fi operations. Therefore, 2.4 GHz and 5.0 GHz are indeed the correct frequencies in which dual-band routers transmit Wi-Fi signals.