A user ran out of USB ports on their laptop but wants to plug in...

A port replicator expands the number and types of ports available to a laptop, including additional USB ports, video outputs, Ethernet, and more. CompTIA A+ identifies port replicators as solutions for users needing greater connectivity, especially when docking stations are unnecessary or unavailable.

Port replicators connect through a single USB or proprietary connector and provide multiple expansion ports instantly. This resolves the issue of limited USB availability without requiring hardware replacement.

NFC (A) is used for short-range communication, not peripheral connectivity. Bluetooth (B) only supports wireless peripherals such as mice and headphones, not wired USB devices. A USB receiver (C) adds wireless capability for one specific device, not general expansion.

Thus, the correct solution is a port replicator.