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'.
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Question: Question: The type of epidemiological study indicated to evaluate, in a population initially exempt from the health problem under study, the association between a risk factor and the onset of the disease is:
Options: <1> Randomized clinical trial. <2> Quasi experimental. <3> Ecological studies <4> Cases and controls study. <5> Cohort study.

Answer: 3

Question: Question: Before a 49-year-old man, asymptomatic, with a family history of a father who died of prostate cancer, a PSA (Specific Prostate Antigen) of 5.9 ng / ml was identified in a routine company control, with a PSA ratio free / Total PSA of 11% and that in a digital rectal examination there is an increase in consistency in the right prostatic lobe, what is the following clinical indication?
Options: <1> Ask the patient to perform a transrectal ultrasound and prostate biopsy. <2> Perform a abdominopelvic CT scan. <3> Start treatment with 5 alpha reductase inhibitors to halve PSA levels. <4> Start combined treatment of LHRH analogues and antiandrogens. <5> Perform a bone scan.

Answer: 1

Question: Question: The reactions in which the kinetics does not depend on the nucleophilic concentration, are reactions:
Options: <1> Radicals <2> SN1. <3> Pericyclic. <4> SN2. <5> None of the above.

Answer:
2