The diagram illustrates a cross-section of a leaf. What are the functions of the parts labelled 1, 2, 3 and 4?
- A1 gaseous exchange; 2 transporting sucrose; 3 transporting water; 4 photosynthesis
- B1 gaseous exchange; 2 transporting water; 3 transporting sucrose; 4 photosynthesis
- C1 photosynthesis; 2 transporting sucrose; 3 transporting water; 4 gaseous exchange
- D1 photosynthesis; 2 transporting water; 3 transporting sucrose; 4 gaseous exchange