Correct Option (a):
Bluetooth technology primarily operates in the 2.4 GHz Industrial, Scientific, and Medical (ISM) radio frequency band, specifically between 2.402 GHz and 2.480 GHz. Wi-Fi technology, on the other hand, can utilize both the 2.4 GHz and 5 GHz frequency bands, depending on the specific IEEE 802.11 standard implemented (e.g., 802.11n, 802.11ac). Newer Wi-Fi standards, such as Wi-Fi 6E, also extend operation into the 6 GHz band. Therefore, statement (a) accurately describes a key difference in frequency band usage.
Incorrect Options:
Statement (b) is incorrect. Bluetooth is designed for establishing Wireless Personal Area Networks (WPANs), facilitating short-range communication between devices like headphones, keyboards, or smartphones. It is not used for Wireless Local Area Networks (WLANs). Conversely, Wi-Fi is primarily employed for creating WLANs, enabling internet access and network connectivity within a limited geographical area. Wireless Wide Area Networks (WWANs) typically refer to cellular technologies such as 4G LTE or 5G, not Wi-Fi.
Statement (c) is incorrect. Neither Bluetooth nor Wi-Fi technology requires a direct line-of-sight between communicating devices. Both technologies utilize radio waves, which can penetrate or diffract around obstacles, allowing for communication even when devices are not visually aligned. While obstructions can attenuate signal strength, line-of-sight is not a prerequisite for their operation.
Statement (d) is incorrect because statement (b) is factually inaccurate.