Task: Question Answering
Input (English): Question: What would be the coefficient of hepatic extraction of a drug and its hepatic clearance if it is known that in a situation of equilibrium the concentration in arterial blood, from the entrance to the liver is 8 g / mL and that of venous blood, from discharge to the same organ, is 4 g / mL? Consider a hepatic flow of 90 L / h: 
 Options:  <1> 4.0 and 360 L / h. <2> 0.5 and 45 L / h. <3> 1.0 and 90 L / h. <4> 0.25 and 20 L / h. <5> 2.0 and 180 L / h.
Output (English): 2