Which of the following most accurately describes the renal threshold of a substance?
a) Renal threshold is the maximum urine concentration attainable.
b) Renal threshold is the maximum speed at which a substance can be reabsorbed in the nephron.
c) Renal threshold is the plasma concentration at which the speed of reabsorption of a substance is maximized.
d) None of the above accurately describe renal threshold.
e) Renal threshold is the maximum glomerular filtration rate attainable.