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'.

[EX Q]: 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
[EX A]: 2

[EX Q]: Question: What amino acids can be bound to a sugar by an O-glycosidic bond? 
 Options:  <1> Ser and Thr. <2> Cys and Ser. <3> Asn and Thr. <4> Lys and His. <5> Val and Leu.
[EX A]: 1

[EX Q]: Question: An essential characteristic of plasmids is: 
 Options:  <1> Be able to integrate into the genome of the host cell. <2> Direct the process of bacterial conjugation. <3> Carry genes for antibiotic resistance. <4> Replicate autonomously. <5> Being circular DNA molecules.
[EX A]:
4