Having worked with setting up Aleph, Voyager & Alma, these older systems have always supported c) both title/instance level and item level holds/requests. These Ex LIbris implementations would support and allow the individual library to apply their local policy.
As a public library patron, the Minuteman Library Network (in Massachusetts) uses Innovative Sierra and allows only title-level requests. I would posit that the average librarian/reader does not care which copy of the popular book is provided (as long as it is the fastest copy to my hands).
As a former circulation librarian in several different academic libraries, item level holds for books can be challenging if a specific copy is held by a faculty member who may not play by the average patron rules for hold/request.
The one place where item specific holds is useful is for bound runs of journals/serials. Being able to request a specific item/volume/issue shortcuts the process. Of course, a title level request can quickly overcome that if there is a free text/additional information field allowed within the hold/request form.
My experience (as a user, a librarian & ILS/LSP implementor) is that allowing title level holds is the more common policy (except for bound journal runs in academic libraries).
Hope that’s helpful.
FOLIO Training Manager, EBSCO