The best response is:

b. The address ends in .gov
Websites that end in .gov are generally reliable because they are connected with our federal or local governments. Don't be fooled by bells and whistles on a website. Just because the web pages look colorful, it doesn't mean that the information is true. A reliable website usually will post: a) the organization's name, b) the author's name, c) a way that the author can be contacted, and d) a list of references. If you are looking for facts, check out a few different web sites and compare information or double check the information at a library.