Question

Ambassadors cannot be arrested, sued, or taxed in the country where they are serving because of _____.

Answer 1

Ambassadors cannot be arrested, sued, or taxed in the country where they are serving because of Diplomatic Immunity, because it's a legal immunity that gives to diplomats privileges and benefits to guarantee a secure passage and also it establishes that diplomats cannot be detained, demanded, or taxed in the host country. Moreover, that legal immunity has an inviolability character, where the diplomats benefits have to be respected by the country where they're serving.

Answer 2

Because of diplomatic immunity. This is a form of legal immunity that makes sure that diplomats are given safe passage and should not be considered susceptive to trial or prosecution under the country's laws, although they can be suspended.  

Hope this helped! :)