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: The generation of the cold vapor is a form of introduction of the sample for the atomization that is used in atomic absorption spectrometry (EAA) to analyze: 
 Options:  <1> Lead and Arsenic. <2> Mercury. <3> Elements that have a low vapor pressure at room temperature. <4> Halogens of high molecular weight. <5> Alcalinotérreos.

A: 2
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Q: Question: If you want to study the efficacy and safety of a new cytostatic for a specific oncological process and, at the same time, contrast the efficacy that adds a new monoclonal antibody to this treatment, what would be the most appropriate study design? 
 Options:  <1> Parallel test. <2> Cross test <3> Factorial test. <4> Sequential test. <5> Test of n = 1.

A: 3
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Q: Question: The first level of heart rate and respiratory control is: 
 Options:  <1> The cerebral cortex <2> Spinal cord. <3> The cerebellum <4> The bulb. <5> The hypothalamus

A:
4
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