Hi Elyana29,
I found a link:
http://humanorigins.si.edu/research/climate-and-human-evolution/climate-effects-human-evolution
A, C, D, and E are all valid options.
often times, when physical models are used instead of actual models, it's because of the actual object's size or composition. that's why we have globes instead of actual models of the earth! they'd simply be too big to keep in a classroom :)
i hope i helped! good luck.
