I think it’s “¿Ustedes cortaron las verduras para la cena esta noche?”
(“Did you guys cut the vegetables for dinner tonight?”)
“Cortaron” is the past tense of “Cortar” which means “Cut”
Whereas if you say “¿Ustedes cortan las verduras para la cena esta noche?” It would be translated into “Are you guys going to cut the vegetables for dinner tonight?”
I think “Cortaron” is the right answer