A patient's dry weight is 154.0 lb (70 kg) and the patient's pre-treatment weight is 158.4 lb (72 kg). For a four-hour treatment, how many mL/hour must the patient lose to reach dry weight?

A. 200 mL/hour
B. 400 mL/hour
C. 600 mL/hour
D. 800 mL/hour