During a respiratory assessment of an infant with respiratory distress syndrome, a sinking in the supraclavicular and intercostal areas of the thorax was noted with inspiration. This observation is documented as:

Retractions

Explanation:

Retraction is a medical terms used for problem associated with hard inhaling due to sinking of area between the neck and ribs. Due to sinking, The intercostal muscle between the ribs helps in filling air in the lungs by pulling the rib cage up. But when the trachea or airway of the lungs get blocked, the air pressure inside the chest reduces due to which the intercostal muscles are pulled inward and hence the retractions arise.