WITH Wronguns AS (SELECT ID, ARRAY_AGG(WrongAnswer) WrongAnswers
                    FROM Questions Q
                     LEFT JOIN (SELECT * FROM WrongAnswers ORDER BY RANDOM()) WA ON Q.ID = WA.QuestionID
                     GROUP BY Q.ID)
  SELECT ID, Question, CorrectAnswer, (WrongAnswers)[1], (WrongAnswers)[2], (WrongAnswers)[3]
    FROM Wronguns W
    NATURAL JOIN Questions Q;