A user wants to download music from a computer to a smartphone.

USB-Cis commonly used for both charging and data transfer between modern computers and smartphones. It supports high-speed data transmission and is a standard port on most new smartphones.

“USB-C cables support power delivery and high-speed data transfer, and are commonly used to connect smartphones to computers.” — CompTIA ITF+ Guide

VGA is for video output.

Thunderbolt is high-speed, but typically used with Apple or specialized hardware.

NFC is a wireless protocol, not a cable.

Correct answer: A