How to determine the place of business of a foreign air carrier for entering into a contract?

Question and answer: Article 33, paragraph 1 of the Montreal Convention provides that: “An action for damages must be filed in the territory of one of the parties, at the option of the plaintiff, in the court of the carrier’s domicile, principal place of business or place of business where the contract is concluded, or in the court of the destination.” Among them, how to determine the “place of business where the carrier enters into a contract” should be handled according to the following ideas: