Final answer:
FTP client software, exemplified by FileZilla, enables the uploading and downloading of files between a local computer and an internet server, using the File Transfer Protocol.
Step-by-step explanation:
The correct answer to the question is A) FTP client software, such as FileZilla. FTP stands for File Transfer Protocol, which is a standard network protocol used for the transfer of computer files between a client and server on a computer network. FTP client software like FileZilla allows users to upload and download files securely between their computer and a server on the internet.