A study showed that the photosynthesis rate of a plant continually increased over a certain period. Then the rate leveled off. During the study, light inten-
sity and temperature remained constant. The only variable was the concentra-
tion of carbon dioxide surrounding the plant. What was the cause of this
variation in photosynthesis rate?
Plsss helppp

The photosynthesis uses carbon dioxide to produces glucose, so the bigger is the concentration, faster the plant will uses it (but that rate have a limit, so it is valid until the limit is achieved, like was explained in the question).

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

i think the answer would d