In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

[Q]: Question: What element plays a physiological role in the prevention of gastroesophageal reflux? 
 Options:  <0> Upper esophageal sphincter <1> Angle of His. <2> Hernia of Hiato. <3> Purkinje angle. <4> Pyloric sphincter
[A]: pharmacology


[Q]: Question: The valvulopathy that triggers an overload of volume in both the left atrium and ventricle is: 
 Options:  <0> Mitral stenosis. <1> Mitral insufficiency <2> Aortic stenosis. <3> Aortic insufficiency <4> Tricuspid insufficiency.
[A]: pharmacology


[Q]: Question: The reaction of 5-Decino with sodium in ammonia and tert-butanol produces: 
 Options:  <0> Dean. <1> cis-5-Decene. <2> 5-Decanamin. <3> trans-5-Decene. <4> 5,6-Decanodiamine.
[A]:
chemistry