The diagram depicts a vertical section of part of the stem of a dicotyledonous plant. Three kinds of structures are labelled. What are the structures U, V and W?
- Acompanion cells: U; phloem sieve tube elements: W; xylem vessel elements: V
- Bcompanion cells: V; phloem sieve tube elements: U; xylem vessel elements: W
- Ccompanion cells: U; phloem sieve tube elements: V; xylem vessel elements: W
- Dcompanion cells: W; phloem sieve tube elements: V; xylem vessel elements: U