Final answer:
Cardiac amyloidosis is a type of restrictive cardiomyopathy that may show restriction and normal wall size.
Step-by-step explanation:
Restrictive cardiomyopathy is a condition in which the heart becomes rigid and is unable to expand and fill with blood properly. One type of restrictive cardiomyopathy that may show restriction and normal wall size is called cardiac amyloidosis. In cardiac amyloidosis, abnormal proteins called amyloids build up in the heart tissue, making it stiff and restricting its ability to pump blood effectively.