A 32-year-old man sustains an iliac wing fracture and a contralateral femur fracture. Twelve hours later he has shortness of breath with tachypnea, hypoxia

A 32-year-old man sustains an iliac wing fracture and a contralateral femur fracture. Twelve hours later he has shortness of  breath with tachypnea, hypoxia, and confusion. A chest radiograph is normal. What is the most likely diagnosis?
a.Fat emboli syndrome
b. Adult respiratory distress syndrome
c. Pulmonary embolus
d.Tension pneumothorax