Personally I would choose a foreign language out of those. If you were to combine it I would go with business- doing law with german isn't any more use than straight law unless you wish to specialise in german/EU law (though a language with any degree does look good). German/business is a really good combination- employers will love you if you have a language, especially german for business, and the placement year abroad is really good for getting internships and furthering career prospects etc.