Final answer:
An abdominal aortic aneurysm (AAA) is a condition where the aorta in the abdomen becomes enlarged and weakened, potentially leading to life-threatening complications if not treated.
Step-by-step explanation:
An abdominal aortic aneurysm (AAA) is a condition where the aorta in the abdomen becomes enlarged and weakened. The aorta is the largest artery in the body, originating from the left ventricle and descending to the abdominal region where it bifurcates into the common iliac arteries at the level of the fourth lumbar vertebra. When the wall of the abdominal aorta becomes weakened, it can bulge or expand to form an aneurysm, which is potentially life-threatening if it ruptures.
The correct answer to the question of what an abdominal aortic aneurysm is would be 1) A condition where the aorta in the abdomen becomes enlarged and weakened. This condition is significant because the aorta distributes blood to virtually all tissues of the body, and a rupture could lead to severe internal bleeding and potentially death without prompt treatment.