If an injured person has obstructed airways, what should we do?

A)Place them in a semi-seated position.
B)Give them mouth-to-mouth resuscitation.
C)Remove from their mouth whatever is causing the obstruction.Correct
If the injured person is not breathing because their airways are obstructed, the first thing we will do is resolve the cause of that obstruction.
To open the airways we will perform the head-tilt chin-lift manoeuvre: with one hand we lift the chin slightly and with the other we push the forehead back.
To open the airways we will perform the head-tilt chin-lift manoeuvre: with one hand we lift the chin slightly and with the other we push the forehead back.