Which of the following difference between Bluetooth and wi-fi is correct ?

• A. Bluetooth uses 2.4 GHz radio frequency band, whereas wi-fi can use 2.4 GHz or 5 GHz frequency band.
• B. Bluetooth is used for Wireless Local Area Networks (WLAN) only whereas wi-fi is used for Wireless Wide Area Networks (WWAN) only.
• C. When information is transmitted between two devices using Bluetooth technology, the devices have to be in line of sight of each other, but when wi-fi technology is used the devices need not be in the line of sight of each other.
• D. Both the statements (Bluetooth uses 2.4 GHz radio frequency band, whereas wi-fi can use 2.4 GHz or 5 GHz frequency band.) & (Bluetooth is used for Wireless Local Area Networks (WLAN) only whereas wi-fi is used for Wireless Wide Area Networks (WWAN) only) are correct in this context.