Final answer:
The 802.11 standard designed to operate at both 2.4 GHz and 5 GHz is 802.11n.
Step-by-step explanation:
The 802.11 standard designed to operate at both 2.4 GHz and 5 GHz is 802.11n. This standard is also known as Wi-Fi 4. It provides faster speeds, improved range, and better reliability compared to earlier standards like 802.11a, 802.11b, and 802.11g.