The answer is Interlibrary Loan
Research consultations typically refer to a service where librarians assist users in developing research strategies, finding resources, and using library tools effectively. It is not a service for requesting full-text articles.
Interlibrary Loan (ILL) is a service that allows library users to borrow books, articles, and other materials from other libraries if their own library does not have access to them. This is the most common service used to request full-text articles that are not available in the library's collection.
Source borrowing is not a standard term used in libraries for requesting articles or materials. It may refer to borrowing sources, but it is not a recognized service like Interlibrary Loan.
Interlibrary Services is a broader term that can encompass various services, including Interlibrary Loan. However, the specific service for requesting articles is typically referred to as Interlibrary Loan.
Document delivery services involve providing users with copies of articles or documents, often for a fee. While it can be related to obtaining full-text articles, Interlibrary Loan is the more specific and commonly used term for requesting items for free.