Rhizome of ginger is a modification of stem because:

Rhizome of ginger is a modification of the stem because it bears nodes and internodes.

The plant's stem can be roughly divided into internodes and nodes.
- Because ginger rhizomes have internodes and nodes, they resemble vascular plants' stems.
- Rhizomes are found underground, and they use nodes outside the ground to send roots and shoots.
- Rhizomes are also known as the plant's creeping root stalks. The axillary buds serve as the starting point for the growth of rhizomes. They develop tropically or perpendicularly to the direction of gravity. The rhizome also has the potential to support the plant's shoot as it continues to climb upward.

Hence, the correct answer is option B.