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: For the analysis of traces of inorganic constituents, in samples of organic nature, a preliminary treatment of the sample is needed, which normally consists of: 
 Options:  <0> Dissolve the sample in cold water. <1> Dissolve the sample in hot water. <2> Dissolve the sample between 30 and 70 ºC. <3> Heat the sample between 400 and 700 ºC. <4> Heat the sample in 0.1 M hydrochloric acid.

A: chemistry
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Q: Question: The determined (or systematic) errors that can be committed in an analytical method: 
 Options:  <0> They cause the data to spread more or less symmetrically with respect to a mean value. <1> They have a definite value and an assignable cause, giving rise to a bias in the results of a series of measures. <2> They come reflected in the precision of a measurement. <3> They are never attributable to instrumental measuring devices. <4> They result in outliers, which differ greatly from the others in a set of duplicate measures data.

A: pharmacology
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Q: Question: Calcium hydroxide: 
 Options:  <0> It is prepared by adding water to calcium oxide. <1> It is a compound of intense red color. <2> It crystallizes when heated. <3> In solution it remains unchanged in air for months. <4> It is used to paint after neutralizing with HCl.

A:
chemistry
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