With no explanation, chose the best option from "A", "B", "C" or "D". of a[AAA] rule to a[AAA] arbitrator, that particular issue of procedure was left for the arbitrator to decide.” Opinion at 1121 (citing Howsam, 537 U.S. at 86,123 S.Ct. 588). Here, neither party disputes the existence nor validity of the arbitration agreement. Therefore, I concur in the majority’s decision to compel arbitration. However, I would remand all other issues to the arbitrator, including the issues of whether the arbitration provision was waived or breached, and therefore dissent to the extent the court holds otherwise. See Howsam, 537 U.S. a 43, 46 (1st Cir.2005) (considering question of waiver after the "AAA dismissed the Tyco demand for arbitration ... for lack of written consent”); PPG Indus., Inc. v. Webster Auto Parts Inc., 128 F.3d 103, 107 (2d Cir.1997) (<HOLDING>); Great W. Mortgage Corp. v. Peacock, 110 F.3d

A: holding that coparties become opposing parties emphasis added within the meaning of fedrcivp 13a after one such party pleads an initial crossclaim against the other with no discussion of whether an opposing party must be deemed a defendant
B: holding that a party waives its right to arbitration when it engages in protracted litigation that prejudices the opposing party emphasis added
C: holding that a party that engages in protracted litigation waives his right to arbitrate when an order compelling arbitration would result in prejudice to the party opposing arbitration
D: holding that a court may consider a theory raised for the first time in a posttrial brief unless it is precluded by the pleadings or it prejudices the opposing party
B.