The agreement, signed at a meeting held in Tunis under the chairmanship of Minister of Transport Mahmoud Ben Romdhane, in the presence of the Director of Congo's Air Transport, the CEO of Tunisair and the Director General of Civil Aviation, also establishes a bilateral co-operation programme in the technical fields, training and exchange of expertise.
Take context from the input text and decide on the accurate relationship between 'Tunisair' and 'Tunis' from the options provided.
Options: headquarters location, member of, operator, location of formation