(1) Proceedings for the recovery of a sum due by a person to Eurocontrol in respect of air navigation services or aeronautical communications services provided by Eurocontrol or any other person shall be brought -

(a) if the residence or, as the case may be, the registered office of the first-mentioned person, is situated in a contracting state, in that state,

(b) if his or her residence or, as the case may be, his or her registered office is not situated in a contracting state, in any contracting state in which the person has a place of business,

(c) if his or her residence or, as the case may be, his or her registered office is not situated, and he or she has no place of business, in a contracting state, in any contracting state in which he or she has assets, or

(d) if his or her residence or, as the case may be, his or her registered office is not situated, and he or she has no place of business or assets, in a contracting state, in the contracting state in which Eurocontrol, for the time being, has its headquarters.