B is the answer.
A doesn’t make sense, animals don’t really help hunters.
D doesn’t make sense either, transportation was good but herds of animals usually weren’t only used for that.
E could make sense but usually they already had an abundance of fur and skins from animals they had killed in the past.
F animals rarely help when preparing land for planting and I doubt they knew how to use them for such things, though it’s possible, it’s very unlikely, especially since they just got them.