Bud : Blossom — select the pair that expresses the same relation.

A bud is not a piece of a blossom; it is the blossom at an earlier stage of its growth, which later opens out. A larva stands in the same way to the insect, being the young form that later becomes the grown creature. 'Branch : Tree', 'Petal : Flower' and 'Root : Plant' all join a piece to the whole it belongs to, and a piece exists at the same moment as the whole rather than growing into it.