Discs of uncooked potato tissue are first weighed to find their initial mass. They are then left in sucrose solutions with different concentrations. After 1 hour, they are weighed again to obtain their final mass. The graph shows how the ratio of initial mass to final mass varies with sucrose solution concentration. Which concentration of sucrose solution has the same water potential as the cells in the potato discs?
- A$0.1\ \text{mol per dm}^3$
- B$0.3\ \text{mol per dm}^3$
- C$0.4\ \text{mol per dm}^3$
- D$0.5\ \text{mol per dm}^3$