The graph illustrates the diameter of a tree trunk at various times. Which statement is correct?
- AX shows the expansion of the trunk as water fills the xylem during transpiration.
- BY shows a reduction in diameter of trunk as water is lost from the xylem due to transpiration.
- CY shows a reduction in diameter of trunk due to water held in tension in the xylem.
- DZ shows the expansion of the trunk as the phloem tissue acts as a sink at night.