Who is recommended be author of outsourced content?

I am currently intend to outsource content creation to freelancers, but don't know who should I put as the author of the text?

1 - Should I create a pseudonym / avatar and place the text in your name? - This seems like a good idea because people like more of "real people".

2 - Should I put the site name only? if yes, should I insert the freelancer as a collaborator in other section?

3 - Should I put the freelancer's name? - This does not seem to be a great option because it could generate little credibilite with public.

4 - In my personal name? But as I intend to have several sites, I think it would be bad for my personal name be associating me the authorship of various texts.

* I'm not native speaker english, sorry for some mistakes.

 

This is my opinion:
If you want to position yourself in the market as an expert in your field then go with your name for personal branding purposes. If you are actually working in a number of different, unrelated niches, then I would go with a pseudonym: you will not be credible if people Google you and find out that you are claiming to be an expert in various, unrelated fields.
I would add your website in the content but wouldn't add the ghostwriter at all. You need to protect your intellectual property and copyright.
To protect your copyright, the ghostwriter should include a statement in the service contract that states that the work they are doing is a work for hire.