Final answer:
Adequate patient hydration is the best method for reducing the risk of contrast-induced nephrotoxicity (CIN), as it helps dilute the media and supports renal elimination.
Step-by-step explanation:
The best method of reducing the risk of contrast-induced nephrotoxicity (CIN) is B. adequate patient hydration. Hydration helps to dilute the contrast media and supports the kidneys in eliminating it from the body, thus reducing the risk of nephrotoxicity. Premedication with corticosteroids, reducing the contrast injection rate, and utilizing a biphasic injection technique are other strategies, but they do not directly address the fundamental concern of facilitating contrast media excretion as efficiently as ensuring adequate hydration does.