instruction:
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.
question:
Question: By means of the angular methods used to evaluate the flow properties of a powder, it is determined: 
 Options:  <0> The ease with which the solid sets in motion. <1> The angle of repose. <2> The flow velocity <3> The resistance to displacement. <4> The density of the powder.
answer:
pharmacology


question:
Question: They are primary lymphoid organs: 
 Options:  <0> Spleen and lymph nodes <1> The spleen and bone marrow. <2> The thymus and the bone marrow. <3> The pineal gland <4> Peyer's plates and tonsils.
answer:
biology


question:
Question: What disease would we suspect in a young patient who reported a frequent history of dysphagia to solids and liquids with impaired food repeated, without clinical symptoms of pyrosis and in which multiple oral esophageal rings with normal mucosa (trachealized appearance) are observed in oral endoscopy? 
 Options:  <0> Herpetic esophagitis. <1> Eosinophilic esophagitis. <2> Candidiasic esophagitis. <3> Cytomegalovirus esophagitis. <4> Adenocarcinoma of the esophagus.
answer:

medicine