With no explanation, chose the best option from "A", "B", "C" or "D". decisions of a magistrate judge is one instance we have held waiver of appellate review results. United States v. Hernandez-Rivas, 348 F.3d 595, 598 (7th Cir.2003) (citation omitted); United States v. Brown, 79 F.3d 1499, 1503-04 (7th Cir.1996) (collecting authority); United States v. Johnson, 859 F.2d 1289, 1294 (7th Cir.1988) (citation omitted). The purpose of this waiver rule is to promote efficiency between the district and appellate courts, so that district courts have the opportunity to nip errors in the bud without requiring them to conduct plenary reviews of proceedings supervised by magistrate judges. See Hernandez-Rivas, 348 F.3d at 598 (citing Thomas v. Am, 474 U.S. 140, 147, 106 S.Ct. 466, 88 L.Ed.2d 435 (1985)); Lockert v. Faulkner, 843 F.2d 1015, 1017-18 (7th Cir.1988) (<HOLDING>); see also Johnson v. Zema Sys. Corp., 170 F.3d

A: holding the rationale of thomas requires waiver to apply to each issue not included in an objection
B: holding that an objection raised in a motion to suppress evidence preserves the issue for appeal despite the lack of further objection at trial
C: holding that the waiver in two previous contracts was insufficient to support waiver of the contract at issue in that appeal
D: holding that the issue of waiver requires an analysis of the specific facts in each case
A.