Final answer:
The abdominal incision commonly used for trauma surgery because it provides quick access to the peritoneal cavity and the ability to extend it easily if necessary is the transverse incision.
Step-by-step explanation:
The abdominal incision commonly used for trauma surgery because it provides quick access to the peritoneal cavity and the ability to extend it easily if necessary is the transverse incision. This incision is made horizontally across the abdomen, allowing surgeons to quickly reach the peritoneal cavity and perform necessary procedures. It can also be extended easily if needed to provide better access to the organs.