IMO (B) too.
A. No indication in the premises or in this option is given how the sale/price of book is going to affect the sale. INCORRECT
B. If manufactures and distributors are not advertising and the people are only supposed to buy recycle product only then in that the published book is only the source by which people can know about the recycle product. Hence by this book sale of recycle product will be increased. CORRECT.
C. Too narrow scope, as it just talk about plastics. Also it doesn't state how it going to affect the sale of recycled products. INCORRECT
D. If all the listed brand of the product uses recycled materials then it would not help to choose the right product by the people. Hence sale would more dominated with Brand Locality rather than based on recycled percentage. INCORRECT
E. People are only supposed to buy recycled products. They are not forced to buy on the proportion of recycled material in a product. Hence out of scope. INCORRECT
Hope this helps...