The diagram illustrates a model used to show mass flow. In a plant, what are the structures W, X, Y and Z, and in which direction does the solution travel 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