A New Way to Fight Screwworm

R1 states that USDA scientists (actor) made NovoFly (artifact). The EPA option wrongly gives the EPA the creator role, but the article only gives the EPA an approval role (R20). The genetic-switch option misattributes a NovoFly feature (R16) as the scientists' direct action. The fly-rearing centers option borrows a later, conditional detail (R21) that describes future use, not who made NovoFly.

R3 states that screwworm is an insect that can hurt farm animals and wild animals. The NovoFly option gives this harmful trait to the wrong actor, since NovoFly is the new fly tool, not the pest. The 'cannot hurt' option reverses the relation's polarity. The crops option over-extends the scope beyond what R3 licenses.

R6 states that the released male flies mate with wild female flies. The first distractor swaps which sex is sterile and which is wild. The second reverses the relation's direction (avoid instead of mate). The third borrows the later egg-outcome mechanism from R7 instead of describing the mating act itself.

In this sentence, R6's process begins with scientists setting the sterile flies loose near wild flies, so 'release' means letting something go into an area. The other options are unrelated senses of 'release': launching a product, excusing someone from duty, or loosening a grip.

R19 links more mating by sterile males to better screwworm control, so 'control' here means limiting and managing the pest. The other options are unrelated senses of 'control': operating a machine, ruling a government, or restraining a feeling.

R7 states that the eggs from this mating do not grow into larvae. The second option reverses this outcome's polarity. The third option borrows NovoFly's genetic-switch mechanism (R15), which is not part of the classic sterile-fly method described here. The fourth option over-extends the scope beyond larvae to 'any insects.'