Wait, this book wasn't made by ETS was it? Because I can't see them ever using such a confusing, number heavy passage in an RC passage.
Anyway, I think the answer is E. They had a higher crop yield over all, but a lower yield if fallow acreage is not included. From that, we can deduce that they had more (or at least higher yield in) fallow acreage than the US, which eliminates all choices but E, although the wording is poorly written and repetitive (all the choices are very similar)... so I'm not entirely sure. Do you have the OA?