DENDROLOGY

Detailed explanation-1: -The primary root, or radicle, is the first organ to appear when a seed germinates. It grows downward into the soil, anchoring the seedling. In gymnosperms and dicotyledons (angiosperms with two seed leaves), the radicle becomes a taproot .

Detailed explanation-2: -The radicle (primary embryonic root) emerges from the seed first to enhance water uptake; it is protected by a root cap produced by the root apical meristem.

Detailed explanation-3: -Note: From all the above options there are different parts of plants given but only plumule is that part of the plant which grows and develops into shoots on germination which are found between the radicle (root part) and cotyledon (leaf part).

Detailed explanation-4: -The root that develops directly from the radicle is termed as true root.