Answer:
Fueron
Explanation:
Fui or fue is the conjugation, and the they/ellos ending is eron
mito
C) duerme
the ud. form is the el, ella, ud form and ends in e (or in a if its a ar verb) and dormir is a stemchanger o to ue. So when you change o to ue and replace ir with e, you get duerme.