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: Controls the passage of substances to the central nervous system: 
 Options:  <0> Meninges. <1> Choroid plexus. <2> Hemato-encephalic barrier. <3> White substance <4> Schwann cells and oligodendrocytes.
answer:
biology


question:
Question: The reaction of an alkene with metachloroperbenzoic acid causes a cyclic ether which is called: 
 Options:  <0> Furano <1> Dioxane <2> Epoxide <3> Azirano <4> Lactone
answer:
chemistry


question:
Question: Regarding gastroesophageal reflux disease, which of the following statements is true? 
 Options:  <0> The intensity and frequency of heartburn has little relationship with the presence and severity of endoscopic esophagitis. <1> Most patients with gastroesophageal reflux disease have esophagitis at endoscopy. <2> Treatment with proton pump inhibitors usually achieves good control of symptoms but is not superior to placebo in the endoscopic cure of esophagitis. <3> Barrett's esophagus can progress to low-grade epithelial dysplasia, high-grade epithelial dysplasia, and finally squamous cell carcinoma of the esophagus. <4> Endoscopic screening and surveillance programs have unequivocally shown to be able to reduce mortality in patients with Barrett's esophagus.
answer:

medicine