An unresponsive 51-year-old male was stabbed in the fourth intercostal space of his left chest an inch lateral to his sternum. His skin is pale, cool, and diaphoretic. His lungs are clear to auscultation, and you observe his neck veins are distended. You should suspect:
a) Tension pneumothorax
b) Simple pneumothorax
c) Cardiac tamponade
d) Flail chest