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.

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.
biology

Question: An essential characteristic of plasmids is: 
 Options:  <0> Be able to integrate into the genome of the host cell. <1> Direct the process of bacterial conjugation. <2> Carry genes for antibiotic resistance. <3> Replicate autonomously. <4> Being circular DNA molecules.
biology

Question: The muscle relaxant suxetonium (succinylcholine), which was designed from decamethonium by substitution of two ethylene groups by two ester functions, susceptible to a hydrolytic metabolism, is a: 
 Options:  <0> Prodrug <1> Hard drug. <2> Apolar drug. <3> Chiral drug. <4> Soft drug

pharmacology