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.

[EX Q]: Question: Which of these species is a free radical? 
 Options:  <0> The molecule NO. <1> The O2 molecule. <2> The N2O molecule. <3> The OH- anion. <4> The ClO- anion.
[EX A]: chemistry

[EX Q]: Question: Indicate which of the following is an acquired corpuscular hemolytic anemia: 
 Options:  <0> Paroxysmal nocturnal hemoglobinuria. <1> Deficit of glucose 6 phosphate dehydrogenase. <2> Minkowski-Chauffard disease <3> Sickle-cell anaemia. <4> Pyruvatokinase deficiency.
[EX A]: pharmacology

[EX Q]: Question: The reaction conditions for transforming nonanamide into octanamine and carbon dioxide are: 
 Options:  <0> H2, metallic catalyst. <1> Excess of CH3I, K2 CO3. <2> Cl2, NaOH, H2O. <3> LiAlH4, diethyl ether and then hydrolysis. <4> CH2N2, diethyl ether.
[EX A]:
chemistry

