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: Regarding gastroesophageal reflux disease, which of the following statements is true? 
 Options:  <1> The intensity and frequency of heartburn has little relationship with the presence and severity of endoscopic esophagitis. <2> Most patients with gastroesophageal reflux disease have esophagitis at endoscopy. <3> Treatment with proton pump inhibitors usually achieves good control of symptoms but is not superior to placebo in the endoscopic cure of esophagitis. <4> Barrett's esophagus can progress to low-grade epithelial dysplasia, high-grade epithelial dysplasia, and finally squamous cell carcinoma of the esophagus. <5> Endoscopic screening and surveillance programs have unequivocally shown to be able to reduce mortality in patients with Barrett's esophagus.
[A]: 1


[Q]: Question: The R-bands of human metaphase chromosomes: 
 Options:  <1> They contain DNA rich in AT pairs. <2> They have high gene density. <3> They contain poor DNA in GC pairs. <4> They replicate at the end of phase S. <5> They have low gene density.
[A]: 2


[Q]: Question: T-independent antigens: 
 Options:  <1> They are mostly proteins. <2> They induce maturation of the affinity of the specific antibodies. <3> Induce isotype change of specific antibodies. <4> They are usually polymeric antigens. <5> They induce intense secondary responses.
[A]:
4