Hint: Shoot is the part of a plant which rises upward from the soil when the seeds germinate. The shoot system consists of stems along with their appendages like leaves, buds, etc.
Option A: Plumule is the part of a seed embryo that will give rise to the shoot system. Upon seed germination, plumules grow upward. They exhibit negative geotropism which means they grow away from the soil. They are known to be positive phototropic because of their growth towards the sun. The plumule or baby shoot eventually grows into the complete shoot system. Therefore this is the correct answer.
Option B: Radicle is the primary root or embryonic root inside the seed. Radicle is the first part that generates from a germinating seed. They exhibit positive geotropism and grow into the soil to form the root system. Plumule is grown after the radicle. Therefore, this is the incorrect option.
Option C: Seed coat is the outermost coating of a seed that protects the seed and acts as a waterproof container. It prevents the entry of excess water into the seed. They are also known as testa and enclose plumule, radicle, cotyledons, and the storage tissue, endosperm. Therefore, this is the incorrect option.
Opinion D: Endocarp is the innermost layer of pericarp which is a protective coating of a seed. These are membranous in some fruits and woody in others. Endocarp cells contain oil droplets. Endocarps are edible in some fruits. Therefore, this is the incorrect option.
Hence the correct answer is option ‘A’, plumule.
Note: In some seeds, the plumule doesn't grow until the cotyledons grow above the ground. This is known as epigeal germination. Whereas in some other seeds, a leaf structure is already present in the embryonic plumule. These plumules can grow when the cotyledons remain underground. This is called hypogeal germination.