Bulb is modified

Which is not a modification of stem?

Give scientific reasons : Opuntia has phylloclade.

Assertion : Many plants are propagated vegetatively even though they bear seeds.
Reason : Potatoes multiply by tubers, apple by cutting etc.

Rhizome of ginger is like the roots of other plants that grows underground. Despite this fact ginger is a stem and not a root. Justify.

Choose incorrect sentence.