0 Longitude is the Prime Meridian
Answer:
C. You cross from the western to eastern hemisphere
Explanation:
I believe this is the most reasonable answer but the question is a little confusing. If it is asking how to travel through different ecosystems then C is the most reasonable as A would only change the temperature and sometimes change the weather. B would keep you underwater all the time and you can't really switch ecosystems unless you got out. D, your staying in one ecosystem when climbing a mountain.
Hope this helps :)
Answer:
A
variations in the population
