A student carried out an investigation into the rate of transpiration in a green plant. The plant was growing in soil inside a pot. After watering the plant, the student placed a plastic bag around the pot while keeping the leaves outside the bag. She recorded the mass of the plant and pot at the beginning, then repeated the measurement every two hours for six hours. The findings from the investigation are shown. What is the mean rate of transpiration during the six-hour period?
- A$43\,\text{g h}^{-1}$
- B$12\,\text{g h}^{-1}$
- C$8\,\text{g h}^{-1}$
- D$4\,\text{g h}^{-1}$