The correct comparison of the functions of the roots and the stems of a plant is as follows:
The stems and the roots are both transportation systems, moving different things the plant needs. However, the roots actually get water and essential nutrients out of the soil, while the stems just deliver these things to where they are needed.
This statement accurately reflects the roles of roots in absorbing water and nutrients from the soil and the function of stems in transporting those nutrients to various parts of the plant.