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: A potential receiver: 
 Options:  <0> It is produced by the opening of voltage-dependent channels. <1> Increase its frequency if the intensity of the stimulus increases. <2> It occurs after the binding of the neurotransmitter to the postsynaptic receptor. <3> They occur if the trigger threshold is exceeded. <4> It can be exciter or inhibitor.

A: biology
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Q: Question: A 72-year-old woman with type 2 diabetes and chronic renal failure in stage 5. If a pulmonary thromboembolism is suspected, indicate which diagnostic test would be contraindicated: 
 Options:  <0> Transthoracic echocardiogram. <1> Pulmonary scintigraphy <2> Pulmonary angioCT. <3> Electrocardiogram. <4> Chest x-ray.

A: medicine
****
Q: Question: Which of the following answers is correct regarding a tRNA? 
 Options:  <0> The tRNA has an anticodon that recognizes the template DNA. <1> The amino acid is attached to the 5'-end. <2> It contains a polyA tail at its 3 'end. <3> It may contain pseudouridin and inosine. <4> It serves as a gene for some viruses.

A:
chemistry
****