Which condition applies to every player seeking an international transfer?

To facilitate an international transfer, it is essential for every player to be licensed by a national member federation. This licensing ensures that the player is recognized and holds the appropriate status to participate in international competitions. It serves as a confirmation of the player's eligibility and adherence to the regulations set forth by the relevant basketball governing bodies, such as FIBA.

Having a license from a national federations signifies that the player has met specific criteria, including age, contract status, and transfer regulations, making them eligible for transferring to international clubs. This requirement is pivotal in maintaining the integrity of the sport and ensuring that all players are governed under the same set of rules and standards.

In contrast, the other options do not universally apply to all players seeking international transfers. For instance, not every player must be a national player or have played in international competitions, as many foreign players transfer internationally without having participated in such events. Thus, being licensed by a national member federation is a foundational requirement for all players intending to make an international transfer.