Which sentence shows ownership correctly? Mandy and Mike's theories about what happened were both good, but Mandy made the better argument. Mandys and Mikes theories about what happened were both good, but Mandy made the better argument. Mandy and Mikes theories about what happened were both good, but Mandy made the better argument. Mandy's and Mike's theories about what happened were both good, but Mandy made the better argument.