Answer: C) Plant D
Explanation:
While the other plants are being tested on, the scientist(s) can always refer back to Plant D because there is no experimenting taking place.
This process is known as thermohaline circulation. In the Earth's polar regions ocean water gets very cold, forming sea ice. As a consequence the surrounding seawater gets saltier, because when sea ice forms, the salt is left behind. As the seawater gets saltier, its density increases, and it starts to sink.
