With no explanation, chose the best option from "A", "B", "C" or "D". here of the level of generality at which it will promulgate norms implementing a legislative mandate.” (citation omitted)). 11 . For example, with respect to cancer risks, a risk threshold might be presented as "1 x 10 A” signifying that an individual "is estimated to have up to a one in 100,000 chance of developing cancer during his/her lifetime from the exposure being evaluated.” Coalition Br. 5; see id. at 35. 12 . See National Wildlife Fed'n v. EPA, 286 F.3d 554, 566-67 (D.C.Cir.2002) (concluding that EPA reasonably interpreted Clean Water Act § 301(b)(2) as permitting it to regulate color pollutants on a case-by-case basis, because their impact "is driven by highly site-specific conditions” (citation omitted)); Chemical Waste Mgmt., Inc. v. EPA, 976 F.2d 2, 31 (D.C.Cir.1992) (<HOLDING>). 13 . See Public Citizen, Inc. v. FAA, 988

A: holding that verbal requirement of need not contained in hunting regulation was addition of substance and thus regulation under apa
B: holding that whether an exchange is substantially contemporaneous must be determined on a casebycase basis
C: holding that the corroborative testing requirement of a rcra regulation was not impermissibly vague and that details can be resolved on a sitespecific casebycase basis
D: holding that a state medicaid agency can review the medical necessity of treatment prescribed by a doctor on a casebycase basis
C.