Which of the following technologies can be used for wireless payments?

A, C, and D – But best/most secure way is NFC – however, the question doesn’t ask for the BEST way. It asks only “which” way can be used. All three:
(A) NFC – near field communications – uses High-Frequency radio waves, which means it’s able to transmit data securely without worry of being intercepted.
(C) IR – InfraRed communications – for sending data to other devices and/or controlling them wirelessly.
(D) LTE can be used to send wireless payments via phone apps