Glucose Is Removed in the Proximal Convoluted Tubules

Glucose is removed in the proximal convoluted tubules.Therefore,glucose is not expected to be found in a normal urine sample.However,glucose is found in the urine of diabetics.Why is this the case?

A) More glucose can pass into the nephron because the concentration of the glucose in the blood is very high.
B) The transport of glucose from the pre-urine back to the blood cannot occur at a rate fast enough to remove all of the glucose from the urine.
C) Glucose is passing from the blood surrounding the nephron and into the pre-urine.
D) Diabetics have active transport of glucose from the blood into the pre-urine when blood glucose levels become very high.