Compound fracture is a serious injury in which the broken bone tears the skin. So in compound fracture as bone tears the skin from inside in cause lots of bleeding and the open wound which makes the site of fracture vulnerable for infections.
More the damage to the bone and soft tissue more will be the chances of infection. If the bone gets the infection then it is more difficult to treat it and lots of antibiotics and multiple surgeries could be required to treat the fracture and infection. In some cases, it can become life-threatening. So the correct answer is B.
I believe you should open the patients mouth and do a swab to check if a piece has come up and to get it out. That is the immediate next thing to do after compressions and before possible mouth to mouth.
