Which of the following is a valid subset of convexity descriptors?

• A. Shallow, Moderate, Hard, Soft
• B. Quick, Deep, Rigid, Loose
• C. Flat, Round, Tight, Spongy
• D. Light, Heavy, Medium, Thick

Answer: (A)

Convexity descriptors describe how a convex ostomy appliance presses against the abdomen to create a seal, and they typically cover two aspects: how deep the convexity is (depth) and how firm or soft the material is (stiffness). A subset that makes sense for describing convexity should include terms from these aspects.

Shallow and Moderate refer to the depth of convexity, while Hard and Soft refer to the hardness or durometer of the convex component. Together, they form a coherent set that covers both dimensions of convexity—depth and firmness—so it’s a valid subset of descriptors.

The other sets mix terms that don’t consistently pertain to convexity descriptors. Some terms describe shape, texture, or weight rather than depth and firmness, and one includes a word like Quick that isn’t a standard convexity descriptor at all. Because of this mismatch, those sets aren’t considered valid subsets for convexity descriptors.