Sucrose is transferred from companion cells into phloem sieve tubes. Which sequence of statements correctly describes this mechanism?
- A$1 \rightarrow 2 \rightarrow 4 \rightarrow 3$
- B$1 \rightarrow 4 \rightarrow 2 \rightarrow 3$
- C$2 \rightarrow 1 \rightarrow 4 \rightarrow 3$
- D$4 \rightarrow 1 \rightarrow 2 \rightarrow 3$