Which of the Following Issues Is NOT Addressed by Tax

Which of the following issues is NOT addressed by tax treaties?

A) what tax disclosures must be made by a visitor to a host country
B) treatment of business and investment income earned by a foreign visitor in the United States
C) treatment of business and investment income earned by a foreign citizen in his home country
D) how to compute the taxable amount in the host country
E) all of the above