first, for clarification, is D the second function?
in your post, you say, "ABC is one of the functions and C is the second." ... is this a typo?
secondly, there is a great article on seo which addresses the "and" in your title... see http://yoast.com/articles/wordpress-seo/
thirdly, as you probably know, when you search for a domain name, the registrar offers up additional options. this could be helpful in brainstorming (even if you don't use any of the suggestions, it may trigger you mind to a new option... see http://www.netsavers.com/DomainSearch/Search
finally, if you have not decided upon a platform, wordpress gets very favorable search engine results.
(i've answered this question as if you are a beginner... please do not be offended if you already know all of this... i used to teach school and i've learned that the best policy is to start at the beginning on a topic).