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'.

Question: What values ​​obtained in an arterial blood gas are considered within the normal parameters in an adult person ?: 
 Options:  <1> PaCO2 65mmHg, PaO2 80mmHg, pH 7.55. <2> PaCO2 35mmHg, PaO2 110mmHg, pH 7.55. <3> PaCO2 35mmHg, PaO2 90mmHg, pH 7.35. <4> PaCO2 80mmHg, PaO2 35mmHg, pH 7.35. <5> PaCO2 20mmHg, PaO2 90mmHg, pH 7.45.
3

Question: Which of the following enzyme complexes catalyzes the reduction of molecular oxygen to water during oxidative phosphorylation? 
 Options:  <1> ATP synthase. <2> Cytochrome c oxidase. <3> NADH-Q oxide-reductase. <4> Q-cytochrome c-oxide-reductase. <5> Succinate-Q reductase.
2

Question: What element plays a physiological role in the prevention of gastroesophageal reflux? 
 Options:  <1> Upper esophageal sphincter <2> Angle of His. <3> Hernia of Hiato. <4> Purkinje angle. <5> Pyloric sphincter

2