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: A 65-year-old man with a history of pancreatic cancer undergoing chemotherapy. Emergency consultation for pain and edema of the entire lower limb from the groin. Which diagnostic test is more cost-effective to confirm the diagnostic suspicion? 
 Options:  <1> Dimer D. <2> Magnetic resonance. <3> Phlebography <4> Venous Doppler ultrasound. <5> Helical CT
4

Question: When administering oxygen therapy to a patient admitted to the emergency room due to exacerbated COPD, you should take into account that: 
 Options:  <1> The flow of oxygen must be high, since respiratory failure is accompanied by hypoxia. <2> The concentration of oxygen is conditioned by the patient's clinical situation. <3> The concentration of oxygen must be equal to the atmospheric concentration, since the patient presents hypercapnia. <4> The flow should be low, since hypoxia is the only stimulus to breathe. <5> The flow must be adjusted to achieve a PO2 greater than 90 mmHg.
4

Question: Before a 49-year-old man, asymptomatic, with a family history of a father who died of prostate cancer, a PSA (Specific Prostate Antigen) of 5.9 ng / ml was identified in a routine company control, with a PSA ratio free / Total PSA of 11% and that in a digital rectal examination there is an increase in consistency in the right prostatic lobe, what is the following clinical indication? 
 Options:  <1> Ask the patient to perform a transrectal ultrasound and prostate biopsy. <2> Perform a abdominopelvic CT scan. <3> Start treatment with 5 alpha reductase inhibitors to halve PSA levels. <4> Start combined treatment of LHRH analogues and antiandrogens. <5> Perform a bone scan.

1