Judgment of the General Court (Fifth Chamber, Extended Composition) of 28 February 2024.#Kingdom of Denmark v European Commission.#State aid – Public financing of the Fehmarn Belt fixed rail-road link – Aid granted by Denmark to Femern – Decision declaring the aid compatible with the internal market – Action for annulment – Whether separable – Admissibility – Concept of ‘undertaking’ – Concept of ‘economic activity’ – Activities involving the construction and operation of a fixed rail-road link – Effect on trade between Member States and distortion of competition.#Case T-364/20.