Question: In a Unified Data Repository (UDR) response, when both 'ETag' and 'Last-Modified' headers are included, what is the preferred validator for conditional GET requests and how should it be utilized?
Option 1: Last-Modified is preferred; use with If-Modified-Since header.
Option 2: ETag is preferred; use with If-None-Match header.
Option 3: Both are equally preferred; either If-None-Match or If-Modified-Since can be used interchangeably.
Option 4: The preference depends on the resource type; no standard utilization header is specified.
Explanation: According to best practices in HTTP response handling, when both validators are present, ETag is considered a stronger validator than Last-Modified due to its ability to identify specific versions of a resource more accurately. Therefore, for conditional GET requests, utilizing the ETag with the If-None-Match header is the preferred approach to ensure the most up-to-date version of a resource is retrieved while minimizing unnecessary data transfers.