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: The solubility of copper hydroxide in the presence of a high concentration of ammonia: 
 Options:  <0> Increased by formation of a complex ion of Cu2 + with NH3. <1> It is not affected because there is no common ion effect. <2> Decreases by common ion effect. <3> It decreases upon oxidation of bromide to molecular bromine. <4> It decreases because the hydroxides are more soluble in acidic medium.
[EX A]: chemistry

[EX Q]: Question: The immersion oil used for microscopic observation: 
 Options:  <0> Protects the sample from the oxidizing effect of air. <1> Lubricate the objective lens. <2> Reduces refraction and increases resolution. <3> It acts as a lens that increases magnification. <4> Avoid dehydration of the preparation.
[EX A]: biology

[EX Q]: Question: The particles of recognition of the signal have as function: 
 Options:  <0> Break the signal sequence. <1> Detect cytosolic proteins. <2> Direct the signal sequences to the ribosomes. <3> Link the ribosomes to the endoplasmic reticulum. <4> Join the mRNA to the ribosomes.
[EX A]:
chemistry