The HTTP job entry in Pentaho Data Integration (PDI) is specifically designed to interact with web servers using the HTTP or HTTPS protocol. It can be configured to perform a GET request to a specified URL, which is the standard method for retrieving or downloading files from a website. The entry allows you to define the target URL and specify a local file path where the downloaded content will be saved, directly fulfilling the requirement of the task.

B. Sqoop import: This job entry is used for transferring bulk data between Hadoop and structured datastores like relational databases, not for downloading files from a web server.

C. Get a files with FTP: This entry uses the File Transfer Protocol (FTP) to download files from an FTP server, which is a different protocol and server type than a standard website (HTTP/HTTPS).

D. Copy Files: This job entry is used for copying files and folders within accessible file systems (local or network shares), but it does not support web protocols like HTTP.

1. Hitachi Vantara - Pentaho Documentation: The official documentation describes the HTTP job entry's function. It states

"The HTTP job entry allows you to do a single HTTP call. You can specify the URL to call and a target file to save the result to."

Source: Pentaho Wiki

"HTTP (job entry)". (The Pentaho Wiki serves as a primary official documentation source for PDI components).

2. Hitachi Vantara - Pentaho Documentation: The documentation for the "Get a file with FTP" job entry confirms its specific purpose: "The Get a file with FTP job entry allows you to get files from a remote server using the File Transfer Protocol (FTP)." This distinguishes it from the HTTP protocol.

Source: Pentaho Wiki

"Get a file with FTP (job entry)".

3. Hitachi Vantara - Pentaho Documentation: The purpose of the "Copy Files" job entry is explicitly defined for file system operations: "The Copy Files job entry allows you to copy one or more files and/or folders to a destination folder."

Source: Pentaho Wiki

"Copy Files (job entry)".