In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Q: Question: Ultraviolet radiation changes the structure of DNA by:
Options: <1> Rupture of phosphodiester bonds. <2> Deamination of nitrogenous bases. <3> Depurinization <4> Formation of cyclobutyl rings of pyrimidines. <5> Hydroxylation of nitrogenous bases.

A: 4
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Q: Question: A 24-year-old boy who, after 3 days of high-risk sexual contact, has numerous pustular, small, very pruritic lesions that progress to minute erosions affecting the entire glans and inner face of the prepuce. Indicate which is, among the following, the most probable diagnostic orientation:
Options: <1> Genital candidiasis <2> Chancroid. <3> Secondary syphilis <4> Balanitis by Trichomonas. <5> Fungal infection by dermatophytes.

A: 1
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Q: Question: One of the following compounds produces liver damage as the main toxic effect:
Options: <1> Diethylene glycol. <2> Methanol <3> Acetone. <4> Benzene. <5> Carbon tetrachloride.

A:
5
****