Question ID:PT2 S4 Q18 Passage:Some cleaning fluids, synthetic carpets, wall paneling, and other products release toxins, such as formaldehyde and benzene, into the household air supply. This is not a problem in well-ventilated houses, but it is a problem in houses that are so well insulated that they trap toxins as well as heat. Recent tests, however, demonstrate that houseplants remove some household toxins from the air and thereby eliminate their danger. In one test, 20 large plants eliminated formaldehyde from a small, well-insulated house. Stem:Which one of the following can be expected as a result? Correct Answer Choice:DChoice A:There will no longer be any need to ventilate the house. Choice B:The concentration of toxins in the household air supply will remain the same. Choice C:The house will be warm and have a safe air supply. Choice D:If there is formaldehyde in the household air supply, its level will decrease. Choice E:If formaldehyde and benzene are being released into the household air supply, the quantities released of each will decrease.