The recycling of municipal solid waste is widely seen as an environmentally preferable alternative to the prevailing practices of incineration and of dumping in landfills. Recycling is profitable, as the
recycling programs already in operation demonstrate. A state legislator proposes that communities should therefore be required to adopt recycling and to reach the target of recycling 50 percent of all solid waste within 5 years.

Which of the following, if true, most seriously calls into question the advisability of implementing the proposal?

(A) Existing recycling programs have been voluntary, with citizen participation ranging from 30 percent in some communities to 80
percent in others.

(B) Existing recycling programs have been restricted to that 20 percent of solid waste that, when reprocessed, can match processed raw
materials in quality and price.

(C) Existing recycling programs have had recurrent difficulties finding purchasers for their materials usually because of quantities too
small to permit cost-effective pickup and transportation.

(D) Some of the materials that can be recycled are the very materials that, when incinerated, produce the least pollution.

(E) Many of the materials that cannot be recycled are also difficult to incinerate.

i would say B also:

although i feel A is incorrect b/c it is out of scope...we don't care how many people have been participating b/c we just want to show that it might not be profitable even if people participate...

in order to weaken the argument we must simply attack the main premise "recycling is profitable" -->the regulator says that b/c recycling is profitable then all the communities should do it....so just look for the answer choices that might show otherwise (that recycling might not be as profitable as we think).

Only B and D call this into question, and D doesn't go far enough b/c it only says "some" of the materials that can be recycled produce the least pollution...if it said that "all" the materials that can be recycled produce the least amount of pollution if incinerated, then it might be more compelling....

B shows that the recycling has only been restricted to the most profitable 20% of the total solid waste, so if the up the % to 50, then they might inevitable have 30% that might not be profitable if recycled....the way it stands B is correct IMO...

got it...thanks, guyz