Which of the following wireless technologies would most likely be used to make a purchase from a vending machine?

802.11X is an authentication standard for wired or wireless networks, not a short-range payment technology.

SFP (Small Form-Factor Pluggable) is a compact, hot-pluggable optical transceiver used for telecommunication and data communication applications, unrelated to wireless payment.

Bluetooth is a medium-range wireless technology suitable for connecting devices like headphones, but for secure, very close-range payments, NFC is typically preferred due to its inherent short distance requirement.

Near Field Communication (NFC) is a short-range wireless technology that enables communication between two devices when they are brought within a few centimeters of each other. It is widely used for contactless payments and data exchange, making it ideal for interacting with vending machines.