Woman experiencing amniotic fluid embolism as the placenta is delivered is in a condition in which the amniotic fluid of that woman had entered into the blood stream and at that spot it could become pulmonary embolism where blood clots could block the lung arteries. So, in order to avoid such reactions oxygen is need to combat this blockage of arteries of lungs. The rest of the option given like firm pressure on fundus is quiet painful and could not stop this reaction.
There are many signs, this may help you with your answer https://www.drugabuse.gov/publications/principles-adolescent-substance-use-disorder-treatment-resear...
