Read the following excerpt from a US court opinion:
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whether a dispute over a side agreement that does not provide for arbitration falls within the CBA’s arbitration clause, is one that this court has not previously addressed. There is a split among the circuits that have spoken on this issue. The Second, Fourth, and Eighth Circuits apply the “collateral” test in determining whether a dispute over a side agreement is arbitrable. Under the collateral test, courts consider the similarity of the side agreement’s subject matter to the subject matter of the CBA. If the subject matter is dissimilar, the side agreement is deemed collateral to the CBA. However, where the side agreement is “integral” to the CBA, courts permit arbitration of disputes over its provisions. See, e.g., Cornell Univ. v. UAW Local 2800, 942 F.2d 138, 140 (2d Cir.1991) ; Adkins v. Times-World Corp., 771 F.2d 829,
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What is the most suitable continuation to the opinion? Your options are:
A. holding that when an arbitration clause has provisions that defeat the remedial purpose of the statute  the arbitration clause is not enforceable and that the language insulating an employer from damages and equitable relief renders the clause unenforceable
B. holding that an addendum to the cba was integral to it and therefore subject to the arbitration clause
C. holding that an aaa arbitration was a private proceeding and therefore that a decision by the arbitrator pursuant to the federal arbitration act did not constitute state action
D. holding that the best way to harmonize a choice of law clause and an arbitration clause is to apply the substantive case law of the named state to the entire agreement including the arbitration clause
E. holding that a letter of understanding was collateral to the cba and therefore not governed by the cbas arbitration clause
Reply with [A, B, C, D, E] only.