it is in correct because you dont need the suffix ben ther for its just yo bailan and you if the word is ellos then it cant be jugabas because that is feminine and ellos is masculine
1 is incorrect because yo is I and the bailaban is talking about other people not you or I, so it should have been yo baílaba, or yo baíle. 2 is incorrect because it’s saying they playing which doesn’t make sense , in other words, it should have been ellos jugaban because you use jugabas for talking to someone else, you can for example ask someone: “tú jugabas?” But can’t say ellos jugabas. Hope this helped :)
