Analogy — Whole and its reproductive stage: Plant : Seed :: ? : Bud Pick the whole entity of which a “Bud” is the immature stage, mirroring “Seed” being the plant’s reproductive unit.

Introduction / Context:
This analogy hinges on developmental stages. A “seed” relates to a “plant” as its reproductive unit/incipient form. Likewise, a “bud” relates to the “flower” as its immature/incipient stage that later blooms.

Concept / Approach:
Preserve “whole : immature/reproductive form” with correct biological pairing.

Why Other Options Are Wrong:

• Leaf/Twig/Fruit: A bud can occur on a twig, but the bud matures into a flower; therefore “flower” is the precise whole-in-development relation sought.
• None of these: Invalid since “Flower” fits exactly.

Final Answer:
Flower