(D)Links to useful information
In general, underlining is used to draw attention to a word or phrase within the text. To achieve such purpose, underlining is used in several cases, such as in titles of play, T.V. programs, plays, etc., to emphasize ideas, in a term about to define and to link useful information. Although underlining a link is optional, it is very common in Word processors documents, such as in Microsoft Word documents, and most webpages.