Scientists investigated how wheat plants absorb potassium ions from chemical fertilisers. The results are shown. What difference is there in the uptake of potassium ions $360$ days after planting, compared with $30$ days after planting?
- A$295\ \text{kg per hectare}$
- B$290\ \text{kg per hectare}$
- C$285\ \text{kg per hectare}$
- D$280\ \text{kg per hectare}$