Which of the following "hidden" locations would provide enough space for information related to drug dealers?

The option referring to document metadata is correct because metadata is essentially "data about data," and it can contain a wealth of information that may not be visible at a first glance. In the context of investigations into drug dealers, document metadata can include details such as the author of a document, timestamps indicating when a file was created and modified, and any changes made over time. This additional layer of information can help investigators establish connections between individuals, track activities, and find evidence of illicit behavior.

The other choices might not reveal hidden information related to drug dealers as effectively as metadata. For instance, while the $MFT (Master File Table) entry can offer information about a file’s existence and its size, it does not necessarily provide contextual insights about the content of the file. A newly-created registry entry may show recent changes or installations on a system but may lack the depth of historical data. Lastly, information located ahead of the file name in the header is typically limited to filenames and may not yield relevant context or evidence concerning the activities of drug dealers.