The correct option is C Both a and b
The roots on the basis of their origin, are classified into two types.They are
a) True roots: The roots which develop directly from the radicle or its branches are known as true roots.
b) Adventitious roots: They arise from an organ other than the root, usually a stem, sometimes a leaf. The formation of adventitious roots makes it possible to vegetatively propagate many plants from stem or leaf cuttings.