John sent an HTTP GET request to get a file from the web server. Which event artifact will identify the request?

The correct choice, which identifies the HTTP GET request made by John, is the Uniform Resource Identifier (URI). The URI is a key component of a web request, as it specifies the address where the requested resource, such as a file, can be found on the server.

When John sends the HTTP GET request, the URI tells the server exactly which file or resource is being requested. This is crucial for the server to process the request and return the appropriate content. Without the URI, the server would not know what specific resource the client is trying to access.

In terms of the other options, while HTTPS represents a secure version of HTTP and can be related to requests, it does not identify the specific request or resource; it just indicates that SSL/TLS is being used for encryption. The destination MAC address pertains to the data link layer and is used for local network communications, not for identifying web requests. The source IP address provides the origin of the request but does not point to the specific resource being requested. Hence, the URI is the most relevant artifact in this context.