<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 25-year-old previously healthy woman is admitted to the hospital with progressively worsening shortness of breath. She reports a mild fever. Her vital signs at the admission are as follows: blood pressure 10070 mm Hg, heart rate 111min, respiratory rate 20min, and temperature 38.1C 100.6F; blood saturation on room air is 90. Examination reveals a bilateral decrease of vesicular breath sounds and rales in the lower lobes. Plain chest radiograph demonstrates bilateral opacification of the lower lobes. Despite appropriate treatment, her respiratory status worsens. The patient is transferred to the intensive care unit and put on mechanical ventilation. Adjustment of which of the following ventilator settings will only affect the patients oxygenation?? A: Tidal volume and respiratory rate, B: Tidal volume and FiO2, C: FiO2 and PEEP, D: Respiratory rate and PEEP, E: FiO2 and respiratory rate,  <response>: This is a multiple choice question about ventilator settings that affect oxygenation in a patient with acute respiratory distress syndrome ARDS. The key points in the stem are:- 25 year old previously healthy woman - Worsening shortness of breath and mild fever- Vital signs show tachypnea, tachycardia, hypoxemia- Exam shows decreased breath sounds and crackles suggesting pneumonia- Chest X-ray shows bilateral lower lobe opacities - Intubated and mechanically ventilated due to worsening respiratory failureTo improve oxygenation in a mechanically ventilated patient with ARDS, the main ventilator settings to adjust are PEEP and FiO2. PEEP helps recruit collapsed alveoli and improves ventilation-perfusion matching. FiO2 directly increases the oxygen content of inhaled air. Tidal volume affects minute ventilation and CO2 elimination but not oxygenation. Respiratory rate affects minute ventilation and CO2 elimination but not oxygenation. The correct answer is C.C: FiO2 and PEEP 