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: Immunoglobulin isotype change affects: 
 Options:  <0> The constant regions of the heavy chains. <1> The constant regions of the light chains. <2> The totality of heavy chains. <3> The entire immunoglobulin molecule. <4> The hypervariable regions of the heavy chains.
answer:
biology


question:
Question: Question linked to the image nº5 62-year-old man, smoker of 20 cigarettes a day for 30 years and hypertensive, who comes to the clinic because of pain when walking in the gluteal area that begins at a distance of 300 meters and disappears with rest at 5 minutes. An Ankle / Arm index is made whose image is attached. Which is the diagnosis? 
 Options:  <0> Critical ischemia of right lower limb. <1> Acute ischemia due to arterial embolism. <2> Chronic ischemia due to left iliac occlusion. <3> Leriche syndrome due to bilateral iliac occlusion. <4> Radiculopathy
answer:

medicine