The function of the kidneys is to cleanse the blood. To do that, kidneys filter almost everything from the blood, and then put most everything back in to the blood One of the substances filtered and then put back is glucose. If a doctor notices that there is glucose in a patient's urine sample, then what would be a reasonable explanation?

I. The patient must be on a low carbohydrate/high protein diet

II. The patient has too many carbohydrates in his/her blood.

III. The patient is dehydrated.

IV. The patient has diabetes.