Answer: Option C should be the best answer
Explanation: If you look at option A it can be ruled out because when population 1 temp, on the graph, changes from 15C to 20C there is a decline according to the arch.
Option B is similar in that population 1 continues to decrease on it's arch with temps from 20C to 25C.
Option C is not incorrect, as population 1 arch has a pinnacle of 15C and population 2 has a pinnacle of 25C respectively.
Option D can also be ruled out because neither populations reach those numbers for their arched graphs.
Therefore option C is correct