The diagram presents a model used to illustrate the mass flow hypothesis of translocation. In a plant, what are the structures W, X, Y and Z, and in which direction does the solution flow along W?
- Aphloem W; xylem X; roots Y; leaves Z; from Z to Y
- Bphloem W; xylem X; roots Z; leaves Y; from Y to Z
- Cphloem X; xylem W; roots Y; leaves Z; from Y to Z
- Dphloem X; xylem W; roots Z; leaves Y; from Z to Y