The correct answer is: keyword search, URL or web link.
To research means to find information about a particular subject you are interested in.
Keyword search looks for words anywhere in the record. If you don't know how to name a subject for a research, look for keywords related to this subject. This also applies if you are looking for a title or an author and don't know their names. After seeing several options of your keyword search, yo will have to refine your search to find the most applicable terms.
A URL is an address that shows where a particular page can be found on the World Wide Web. URL is an abbreviation for 'Uniform Resource Locator'.
A weblink is a link from a hypertext file to another location or file. It is typically activated by clicking on the highlighted word, icon or phrase.