Hint: The young shoot of a plant embryo which are present in between the root part and the leaf part of the plant i.e., hypocotyl. This part develops into shoots on germination.
> Option A, Radicle is a part of the plant embryo and it is a primary root which develops first when the seeds germinate. It is an embryonic root which grows downward to the soil. So, radicle is not that part of the plant which grows and develops into shoots on germination as this is the first organ to arrive during that time.
> Option B, Plumule. It is the stem of a plant embryo or you can say it is the young shoot of a plant embryo which is found above the cotyledons. It moves away from the soil and it arises from the region between radicle and the cotyledon which is hypocotyls. So, this can be the part of seed which grows and develops into shoots on germination.
> Option C, Cotyledon. It is an embryonic leaf which is the first leaves to appear during the germination but in the questions that part is asked which develops into a shoot. So, this cannot be the correct option as per the question.
> Option D, Ovule. Ovule is the structure which contains reproductive cells and it develops into seeds when it is fertilised. In other words, ovule is the organ which forms seeds of the flowering plants. These are born in the ovary of a flower. This option is clearly not the correct one. From the above options it is clear that plumule is the right answer which develops into shoot on germination.
Hence, The correct answer is option (B).
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). These are the young shoots of a plant embryo.