A 23-year-old healthy m ale volunteer received an intravenous dose of 2 m g of a new drug during a clinical trial. The drug followed a rst-order, one-com partm ent m odel kinetics and had a volum e of distribution of 10 L. After 6 hours the plasm a concentration of the drug was 50 µg/L. Which of the follow ing was m ost likely the half-life of the drug (in hours)? A. 1 B. 2 C. 3 D. 4 E. 5 F. 6