An adult female is found unresponsive after being shot in the chest. Which one of the following AEMT statements about this patient is of MOST concern?

A) "She does not have any jugular venous distention."
B) "I see an entry wound but no exit wound anywhere."
C) "She is getting more difficult to ventilate."
D) "Her SpO2 has gone from 90 percent to 93 percent."

Answer: C