Read the following excerpt from a US court opinion:
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contended for the first time at oral argument (and afterwards in a letter filed under 5th Cir. R. 28(j)) that the district court's determination was tantamount to finding him responsible for (1) the “reasonably foreseeable acts” of co-conspirators under U.S.S.G. § IB 1.3; (2) having “transferred any firearm ... with ... reason to believe that it would be used or possessed in connection with another felony offense” under U.S.S.G. § 2K2.1(b)(6); and (3) having committed first degree murder under § 2A 1.1, without addressing any of those guideline provisions. Because it was not properly briefed on appeal, that argument is waived. NLRB v. Seaport Printing & Ad Specialties, Inc., 589 F.3d 812, 816 n. 7 (5th Cir.2009); see also United States v. Thames, 214 F.3d 608, 611 n. 3 (5th Cir.2000) . 14 . See Bell, 371 F.3d at 244 ("Our concerns
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What is the most suitable continuation to the opinion? Your options are:
A. holding that an inadequately briefed assertion is waived on appeal
B. holding that failure to raise issue in brief constitutes waiver of appeal of the issue
C. holding that inadequately briefing an issue constitutes waiver
D. holding that partys failure to develop issue in argument section constitutes waiver of issue
E. holding that failure to brief an argument constitutes waiver
Reply with [A, B, C, D, E] only.