Factory farms now produce most of the products.

　　题干大意：工厂农场现在生产大部分的产品。定位到文中第一段的第五句，“The small family farms that used to produce most of the products have been largely replaced by factory farms.”，过去大部分生产的商品的小家庭式农场大量地被工厂式农场所取代。题目与原文意思相符，故选A。