题目选项分析

Something must be done to stop spam. In early days, people seldom received unsolicited email advertisement; but now that numerous bulk email software and email address finders are developed to collect email address all around the world. Advertisers use email addresses to market their products and even sell such email lists to other advertisers. As a result, almost everyone ever get junk email, and sometime several and even tens of annoying emails a day. So, relevant antispam regulations should be framed to stop unsolicited advertising.

The two portions in boldface play which of the following roles?

【选项】Pre-evidence that argument includes and a method that helps to supports that conclusion