Which load does xylem carry from the roots to the rest of the plant?
Explanation
Xylem takes up what the roots have absorbed, namely the water that enters the root hairs together with the mineral ions dissolved in that water, and moves the whole load upwards. Sugar has no place in this load, because sugar is built in the leaves and is loaded into the other transport tissue, so a description that puts sugar in xylem is really describing phloem.