With no explanation, chose the best option from "A", "B", "C" or "D". jurisdiction under 26 U.S.C. §§ 6213(a), 6214(a) and 7442. We have jurisdiction to review that court’s grant of summary judgment under 26 U.S.C. § 7482. Our review is plenary. See Lerman v. Commissioner, 939 F.2d 44, 46 (3d Cir.1991). II. DISCUSSION CIGNA contends that it was error for the Tax Court to uphold the deficiency assessments because the method CIGNA used in calculating its tax liability complied with all applicable laws and regulations. CIGNA’s primary argument is that because none of the regulations adopted by the Commissioner in 1983 explicitly covers a group acquisition, it was free to follow any reasonable method to calculate the net operating loss of the members of the acquired INA and PHC Groups. See Gottesman & Co. v. Commissioner, 77 T.C. 1149, 1981 WL 11396 (1981) (<HOLDING>). It disagrees with the Commissioner’s position

A: holding that validity of regulations will be sustained as long as  reasonably related to the purposes of the enabling legislation 
B: holding that where a regulation could not fairly be read to have spoken at all on an issue an agencys proposed interpretation of the regulation as it pertained to that issue was not a reasonable interpretation of the regulation
C: holding that procedures that are implicit and incidental to procedures otherwise explicitly provided for in a properly adopted rule or regulation do not require further codification by a further adopted rule or regulation and to hold otherwise belies statutory intent   and that such an argument based on the lack of a rule or regulation to cover every step of the testing procedures  is not only speculative and theoretical but also hypertechnical
D: holding that after commissioner proposed two conflicting regulations but adopted neither leaving no regulation in place the taxpayers choice of one of the proposals was reasonable and would be sustained
D.