Final answer:
The most accurate MLA citation format from the provided options for an unsigned article from a website is option (a), but it reflects an older version of MLA style and would need updates to match current standards, such as removing "Web" and the optional inclusion of the access date.
Step-by-step explanation:
The correct MLA format for citing an unsigned article from a website is to use quotation marks for the article title, italicize the website title, and provide the publisher, publication date, and the URL (if applicable). Since an author is not available, the title of the article is used at the beginning of the citation. The current MLA guidelines don't require the inclusion of the word "Web" or the access date. Among the options provided, none exactly fits the current MLA standards for citing a web source. However, the most accurate format based on the older MLA style before the 8th edition would be option (a), though "Web" is no longer necessary and access date is optional.