72Second, it also follows from the Court’s case-law that, while it is ultimately for the national court, which has sole jurisdiction to assess the facts and interpret the national legislation, to determine whether and to what extent the legislative provision in question is justified by such an objective reason, the Court of Justice, which is called on to provide answers of use to the national court in the context of a reference for a preliminary ruling, may provide guidance based on the documents in the file of the case in the main proceedings and on the written and oral observations which have been submitted to it, in order to enable the national court to give judgment (see, to that effect, inter alia, Seymour-Smith and Perez, paragraphs 67 and 68 and the case-law cited).