To What Extent Is LLM Performance on Multiple-Choice Questions Driven by Data Leakage? A Case Study with Contamination-Controlled Spanish Undergraduate Exams. - Eva Sánchez-Salido; Adrián Ghajari Espinosa; Guillermo Marco; Julio Gonzalo 001; Jesús Abizanda; Roser Morante; Alejandro Benito-Santos; Laura Plaza; Jorge Carrillo-de-Albornoz; Víctor Fresno; Enrique Amigó; Andrés Fernández García (Inteligencia Artif., 2025)