The correct option is D Plumule
The active growing region in a dicot embryo which forms shoot is the plumule. The plumule is the young shoot of a plant embryo above the cotyledons, consisting of the epicotyl and often of immature leaves. The young shoot or plumule, is said to be negatively geotropic, because it moves away from the soil it rises by the extension of either the hypocotyl.
Thus, the correct answer is option D.