|Question 12Verbal

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Some fuel additives contain cerium oxide nanoparticles (CeO₂-NPs), which can leach into waterways and soils via wastewater. In a 2015 study, Maël Garaud and colleagues found that CeO₂-NPs can accumulate in the bodies of zebra mussels (Dreissena polymorpha). While bioaccumulation of manufactured nanoparticles may be inherently worrisome, it has been hypothesized that CeO₂-NP bioaccumulation in invertebrate like D. polymorpha could serve a valuable proxy role, observing the need for manufacturers to conduct costly and intrusive sampling of vertebrate species—such as rainbow trout (Oncorhynchus mykiss), commonly used in regulatory compliance testing—for manipulative bioaccumulation, as environmental protection laws currently require.
Which finding, if true, would most directly weaken the hypothesis presented in the text?
When D. polymorpha and O. mykiss are exposed to similar levels of CeO₂-NPs, concentrations of CeO₂-NPs in animals of both species show little variation from individual to individual.
A
The rate of CeO₂-NP uptake in D. polymorpha differs from the rate of CeO₂-NP uptake in O. mykiss in a way that is not yet well understood by researchers.
B
D. polymorpha has been shown to accumulate several other types of manufactured nanoparticles in addition to CeO₂-NPs, whereas O. mykiss has been shown to accumulate only CeO₂-NPs.
C
Compared with O. mykiss, D. polymorpha can accumulate detectable CeO₂-NP concentrations with significantly fewer negative effects.
D