Enviromental because it has to do with pollution.
I’m pretty sure cardiovascular endurance
1 Gallon = 3785 mL
5mL used in = 1 day
1 mL used in = 1/5 day
1 Gallon used in = 3785 / 5 = 757 days
I'm sure the answer you are looking for is specific to your class, but I would say that the nurse should provide something like, "The tumor is most likely benign, but until we test further, we can't know if it's malignancy."