Task: Text Categorization
Input (English): Question: Which of the following conditions causes a decrease in the O2 saturation of the hemoglobin that is not due to a decrease in the partial pressure of oxygen? 
 Options:  <0> Ventilation-perfusion ratio lower than normal. <1> Anemia. <2> Carbon monoxide poisoning. <3> Hypoventilation. <4> Shunt venoarterial.
Output (English): medicine