The correct option is B base of stem
Wheat is a monocot plant and has a fibrous root system. In case of fibrous root, the primary root is short-lived and is replaced by a large number of roots. These roots originate from the base of the stem.
Lateral roots, such as secondary and tertiary roots, are not seen in fibrous root as the primary root is short-lived.
Plumule gives rise to the shoot in the plant.