Answer:
C. El sábado mi mamá pintó la casa
Step-by-step explanation:
The indicative past tense conjugation of pintar as a verb is:
yo pinté
tú pintaste
él/ella/usted pintó
nosotros pintamos
vosotros pintasteis
ellos/ellas/ustedes pintaron
The sentence refers to "mi mamá" as the subject, which would use the conjugation "pintó".