[Solved] An infant's sibling always jumps off his bed with a loud bang after he wakes up from his nap. He then comes downstairs and greets the infant with a tickle, making the infant laugh and cough reflexively. Eventually, the infant begins to laugh and cough reflexively when he hears the bang, even before he sees his brother. In this scenario, the loud bang is a(n) A)conditioned stimulus. B)unconditioned stimulus. C)conditioned response. D)unconditioned response. Arterial changes: Modifications or alterations in the arteries, often related to aging, disease processes, or lifestyle factors, affecting blood flow and cardiovascular health. Sinoatrial Node: A group of cells in the right atrium of the heart that initiates the electrical impulses determining the heart rate, often called the heart's natural pacemaker. Atherosclerotic Changes: Alterations in blood vessels characterized by the accumulation of fatty deposits along their inner walls. Internal Bleeding: Bleeding within the body that can result from injury or illness, potentially leading to serious health complications without immediate treatment.