Case C-843/19: Judgment of the Court (Eighth Chamber) of 21 January 2021 (request for a preliminary ruling from the Tribunal Superior de Justicia de Cataluña — Spain) — Instituto Nacional de la Seguridad Social (INSS) v BT (Reference for a preliminary ruling — Social policy — Equal treatment for men and women in matters of social security — Directive 79/7/EEC — Article 4(1) — Voluntary early retirement — Early retirement pension — Eligibility — Requirement for the pension amount to be received to be at least as much as the legal minimum amount — Proportion of workers of each sex excluded from the benefit of early retirement — Justification of a potential particular disadvantage to female workers — Social policy objectives of the Member State concerned)