With no explanation, chose the best option from "A", "B", "C" or "D". creditor, whether or not' the claim of such creditor is provided for by the plan, and whether or not such creditor has objected to, has accepted, or has rejected the plan.” 11 U.S.C.A. § 1327(a). Thus, courts have ruled that “[t]he Order of Confirmation is res judicata as to all justiciable issues decided or which could have been decided at the hearing on confirmation.” In re Guilbeau, 74 B.R. 13, 14 (Bkrtcy.W.D.La.1987); In re Russell, 29 B.R. 332, 335 (Bankr.E.D.N.Y.1983); In re Lewis, 8 B.R. 132, 137 (Bankr.D.Idaho 1981); Collier, Collier on Bankruptcy ¶ 1327.01 (15th ed. 1991). It is clear that the IRS had ample opportunities to raise the eligibility issue, including before, during, and after confirmation. Therefore, the IRS is now barred from raising the issue unless i io 1983) (<HOLDING>). Therefore, the IRS cannot rely upon section

A: holding that the language of the statute is mandatory and the commission must act within 180 days
B: holding that a request made within 180 days of a modified confirmation order  entered three months after the original confirmation order  but more than 180 days after the original confirmation order was timebarred
C: holding  1330a motion not now justiciable because not raised within 180 days of confirmation
D: holding  1330a motion untimely when filed over 180 days from confirmation
C.