Vascular ring vs tracheomalacia

A) Both are conditions of the aorta
B) Vascular ring involves compression of the trachea, while tracheomalacia is a softening of the tracheal cartilage.
C) Vascular ring involves softening of the tracheal cartilage, while tracheomalacia is a compression of the trachea.
D) Both are conditions affecting the lungs