(A) compensation shall not be denied or reduced to an individual solely because he files a claim in another State (or a contiguous country with which the United States has an agreement with respect to unemployment compensation) or because he resides in another State (or such a contiguous country) at the time he files a claim for unemployment compensation;

(B) the State shall participate in any arrangements for the payment of compensation on the basis of combining an individual’s wages and employment covered under the State law with his wages and employment covered under the unemployment compensation law of other States which are approved by the Secretary of Labor in consultation with the State unemployment compensation agencies as reasonably calculated to assure the prompt and full payment of compensation in such situations. Any such arrangement shall include provisions for (i) applying the base period of a single State law to a claim involving the combining of an individual’s wages and employment covered under two or more State laws, and (ii) avoiding duplicate use of wages and employment by reason of such combining;