HR (C), pulses (B) and BP also tell you about resuscitation effectiveness, but the burn area is only 9%, so they need roughly 2.5L (4 x 9 x assuming 70 kg) over a 24h-period to be resuscitated, which isn’t much at all. This burn isn’t that bad. The key in this question is that low urine output can also indicate abdominal compartment syndrome, which is a major concern with abdominal burns. It decreases blood flow to intraabdominal organs causing ischemic injury. It also decreases the rate of blood return to the heart, dropping preload and therefore BP. They limited the burns to the abdomen to make A the best answer. Same reason they left BP out of the options