Your Remote Pilot test score sheet will contain a list of codes to help you figure out which questions you got wrong.
These codes look like "UA.I.E.K3C", and while they don't correlate to a specific question, they do correlate to a specific knowledge area.
You can look up the UAS codes in the booklet found at this link (the link changes as they update it, please let me know if it's a dead link. You can also search Google for "UAS ACS codes").