Answer
Articles 107–109 TFEU — state aid that distorts competition is in principle incompatible with the internal market unless authorised by the Commission.
💡The Commission is the central enforcer; some aid is block-exempted.
Consolidated TFEU (EUR-Lex) — eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:12016E/TXT