A veterinarian was studying suspected causes of enteroliths, concretelike balls in the colons of horses. She suspected that a diet of mostly alfalfa could be a cause. In a study conducted at a veterinary research facility she examined the records of 62 horses with enteroliths (cases) and compared them with the records of 75 horses free of enteroliths (controls). To assess the conjecture that horses that are fed primarily alfalfa are m prone to getting enteroliths she should test the following hypothesis where: OA. Pcase Pcontrol = 0.4507 vs. Ha: Pcase - Pcontrol > 0.4507. OB. Ho: Pcase - Pcontrol = 0 vs. Ha: Pcase - Pcontrol > 0. OC. Ho: Pcare -Pcontrol = 0 vs. Ha: Pcase - P control > 0. OD. HO: Pare-Pcontrol = 0.4507 vs. Ha Pcase - Pcontrol > 0.4507.