You seem to have answered the question within its-self, R is the answer i believe.<span />
Answer:
C
Explanation:
FBAO: Foreign body airway obstruction (or foreign object airway obstruction)
When your airways are completely obstructed you can't speak properly. Vocal chords make sound out of air, once the air is gone, speaking goes with it. Because she can speak it is only mild FBAO.
Either let them know you are there or check your blind spots
