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: Which glands are located between the skin and the masseter muscle, in front and under the outer ear? 
 Options:  <0> Parotid glands <1> Submandibular glands <2> Sublingual glands <3> Mouth glands <4> Lieberkühn's glands.
[A]: pharmacology


[Q]: Question: The main mediators of the antibody-dependent cellular cytotoxicdiad are: 
 Options:  <0> The eosinophils. <1> The NK lymphocytes. <2> The mast cells <3> The neutrophils. <4> The CD8 + lymphocytes.
[A]:
biology