The stimulus tells us that farmers use antibiotics to increase meat yields. From this we can logically say that the termination of antibiotic use would lead to a decreased meat yield, as compared to when antibiotics are used. In the last sentence, the stimulus says that reduced meat yields will lead to farmers going out of business.
So the chain of causality is as follows: if farmers phase out antibiotics, they will have reduced meat yields, which will in turn lead to them going out of business. If farmers found an alternative way to increase meat yields, this causal chain would be broken. That's captured in answer choice E.
