The graph displayed has no labels on either axis. Which row gives suitable axis labels that would account for mass flow in phloem?
- Ax-axis: distance from sink / $\text{m}$; y-axis: hydrostatic pressure / $\text{kPa}$
- Bx-axis: hydrostatic pressure / $\text{kPa}$; y-axis: distance from sink / $\text{m}$
- Cx-axis: distance from source / $\text{m}$; y-axis: hydrostatic pressure / $\text{kPa}$
- Dx-axis: hydrostatic pressure / $\text{kPa}$; y-axis: distance from source / $\text{m}$