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.
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Question: Question: What amino acids can be bound to a sugar by an O-glycosidic bond?
Options: <0> Ser and Thr. <1> Cys and Ser. <2> Asn and Thr. <3> Lys and His. <4> Val and Leu.

Answer: chemistry

Question: Question: In relation to the treatment of a non-smoking woman with non-small cell lung carcinoma, stage IV adenocarcinoma, which of the following statements is correct?
Options: <0> The determination of the epidermal growth factor receptor (EGFR) mutation is required. <1> Entry Gefitinib is the standard treatment without EGFR determination. <2> It has a standard treatment based on camptothecins. <3> Any type of standard chemotherapy is valid. <4> There is no predictive factor for this disease.

Answer: medicine

Question: Question: Nitric oxide:
Options: <0> It is synthesized from methionine. <1> Activates cAMP-dependent protein kinase (PKA). <2> It binds to receptors coupled to G proteins (GPCR). <3> Induces relaxation of the vascular endothelium. <4> It binds to receptors with protein tyrosine kinase (PTK) activity.

Answer:
chemistry