Final answer:
The correct score for an absence of wall thickening in the grading of cardiac wall motion is Score 3, which represents more severe impairment of myocardial movement.
Step-by-step explanation:
In the context of evaluating cardiac wall motion, a scoring system is often used to grade the degree of wall motion abnormalities. When there is an absence of wall thickening, which is indicative of abnormal or dysfunctional myocardial movement, the scoring system would assign a higher score to reflect the severity of the impairment. The correct score for an absence of wall thickening is Score 3. This score is typically associated with hypokinesis or more severe motion abnormalities, such as akinetic or dyskinetic wall motion where the expected movement and thickening of the myocardial wall are significantly reduced or absent.