With no explanation, chose the best option from "A", "B", "C" or "D". validity of the debt. R. at 47-69; see 38 C.F.R. § 1.911(c) (explaining that a debtor “has the right to informally dispute the existence or amount of the debt, to request waiver of collection of the debt, to a hearing on the waiver request, and to appeal the [VA] decision underlying the debt,” all of which “can be exercised separately or simultaneously”). The RO’s failure to issue an SOC as to the disputed amount of the debt means that that issue was not finally decided by the RO and is still pending below. See 38 U.S.C. § 7105(d)(1) (stating that, after the AOJ receives a timely NOD, it “will take such development or review action as it deems proper” and, “[i]f such action does not resolve the disagreement,” it “shall prepare a[n SOC]”); Tablazon v. Brown, 8 Vet.App. 359, 361 (1995) (<HOLDING>). Accordingly, the Board erred in failing to

A: holding that a board affirmance of an ro decision subsumes that decision
B: holding that the ros failure to issue an soc prevented the disputed ro decision from becoming final and appealable to the board and the claim therefore remained pending
C: holding that the boards finding that a matter was not before it because a substantive appeal had not been filed was error and determining that because a timely nod had been submitted and the ro never responded by issuing an soc as required by law and regulation the proper remedy was to vacate the board decision as to the matter and remand to the board for appropriate procedural compliance specifically the issuance of an soc
D: holding that a claim before an ro remains pending until a final decision is rendered
B.