With no explanation, chose the best option from "A", "B", "C" or "D". to file on time was not due to willful neglect. See I.R.C. § 6651(a)(1). On the face of the matter, these determinations would seem to apply equally to the remainder of the penalty (which was calculated according to the same statutory algorithm and imposed for precisely the same late filing). The Commissioner has pointed to no basis for treating one portion of this unitary penalty differently from the other, and the record suggests no such distinction. The whole is but the sum of its parts, and logically, the two portions of the late-filing penalty should stand or fall together. There may be special circumstances that would justify splitting the baby, but the Commissioner has the burden of identifying those circumstances. Cf. Estate of Abraham v. Comm’r, 408 F.3d 26, 35 (1st Cir.2005) (<HOLDING>). Absent a plausible explanation, the only

A: holding that a second deficiency notice issued for a taxable year was valid where it determined a deficiency in a different type of tax than did the earlier deficiency notice
B: holding that a party is not entitled to pursue a separate action for deficiency judgment where the foreclosure complaint includes a prayer for a deficiency judgment and the foreclosure court reserves jurisdiction to enter a deficiency judgment
C: holding that where notice of deficiency fails adequately to describe the basis on which the commissioner relies for his deficiency determination burden shifts to the commissioner to prove the accuracy of the deficiency determination
D: holding no jurisdiction when trial court granted extension because it found deficiency even though it was not same deficiency complained of by appellant in his motion to dismiss
C.