Final answer:
The correct form is 'leyó', which means 'read' in Spanish.
Step-by-step explanation:
Anoche tu madre leyó el periódico después de volver a casa.
'Leyó' is the correct form of the verb 'leer' (to read) in the third person singular (él, ella, usted) in the past tense. In this sentence, it is expressing that last night your mother read the newspaper after returning home.
Learn more about Spanish verb conjugation