[求助]TT GWD4-38怎么都想不明白

Many residents of Calovia are committed to using products containing recycled materials. Soon these consumers will get help in identifying such products from a book being published by the Calovian government.  The book offers a comprehensive listing, by product type and brand, of goods sold in Calovia that contain recycled material. Therefore, publication of the book will almost certainly increase the use of products containing recycled materials in Calovia.

Which of the following, if true, most strengthens the argument?

A.   Proceeds from the sale of the book are not expected to exceed the cost of its publication.

B.    For numerous types of products, there are many brands that use recycled materials, although their manufacturers and distributors do nothing to advertise those brands’ recycled content.

C.   For many materials, such as plastics, the recycling process results in a lower grade of material with a correspondingly different range of uses.

D.   For many types of products listed in the book, all the brands available in Calovia use recycled materials.

E.    Many manufacturers of products that contain recycled materials vary the proportion of recycled materials in those products in response to changes in price and availability.

哪位大虾帮忙解释一下，为什么这题选B呢？看起来似乎没有什么关系的样子啊。

呵呵，意思是政府帮忙做广告推销了

以前没广告推销，而政府的这本书就起到这个效果了

不选D选项，是不是因为many这个词用得不好？