A 30-year-old man is in the preoperative holding area with a heart rate of 70 beats per minute and an estimated stroke volume of 70 mL. He is breathing 10 times per minute with a tidal volume of 500 mL and an estimated dead space of 100 mL. What is this patient's ventilation/perfusion ratio?
A. 0.5
B. 0.8
C. 1.0
D. 1.2
E. 1.5