is there a Typo or is it supposed to be worded this way ?

Answer choice C - it says " some painters are dancers, since some painters are musicians, and some musicians are dancers." is it supposed to say and some musicians are dancers or is it then some musicians are dancers. because I am unsure how it makes sense with the flaw and all if it said" some painters are dancers, since some painters are musicians, and some musicians are dancers." Help please haha