Trаnstrаcheаl O2 therapy (TTOT) shоuld be cоnsidered as an оption for what patients requiring long-term O2 therapy?I. those who remain hypoxemic with standard approachesII. those who are compliant when using other devicesIII. those who exhibit complications with nasal deliveryIV. those who prefer TTOT for cosmetic reasonsV. those who have decreased mobility