which is best from innerpage link to homepage?

1, <a href="index.htm(or default.htm) ">keword</a>
2, <a href="http://www.youdomaindotcom">keword</a>
3, <a href="/">keword</a>
there are three link ways to homepage ,which is best from SEO eye?
or any better way?

 

Use proper anchor text.. thats the best thing what i have seen

 

I've heard many people say that option number 2 is best:
<a href="http://www.youdomaindotcom">keword</a>
Always use full url

 

No proof yet but I would prefer the full url version.

 

No. 1 is out of the question, unless you consistently advertise your site with the index.htm included (but I don't think that's a good idea).

I'm not sure if google puts any difference in valuation between / and the full URL.

 

Use the full url. This is what i have always used for links.