Classification — part–whole vs co-hyponyms: Identify the pair that is NOT a part–whole relation: Tree : Stem, Face : Eye, Chair : Sofa, Plant : Flower.

Introduction / Context:
Three options express a part–whole relation (component belongs to a larger whole). One option lists two coordinate items within the same category (both are types of furniture) rather than part–whole.

Given Data / Assumptions:

• Tree : Stem → stem is part of a tree.
• Face : Eye → eye is part of a face.
• Plant : Flower → flower is part/product of a plant.
• Chair : Sofa → co-hyponyms; neither is a part of the other.

Concept / Approach:
Classify each as component-of vs kind-of. Only one pair is kind-of at the same level (furniture types).

Step-by-Step Solution:
1) Confirm component relations for A, B, D.2) Identify that C is two wholes of the same super-category (furniture).3) Therefore C is the outlier.

Verification / Alternative check:
Try “remove the right-hand item from the left-hand”: possible for A, B, D; not meaningful for C.

Why Other Options Are Wrong:
They are genuine part–whole or organism–part relations.

Common Pitfalls:
Overlooking that a flower is indeed a part (reproductive structure) of a plant.

Final Answer:
Chair : Sofa