With no explanation, chose the best option from "A", "B", "C" or "D". to make a dispute over arbitrability a dispute “thereafter arising out of’ a contract containing the arbitration provision. The second portion of 9 U.S.C. § 2 provides for enforcement of “an agreement in writing to submit to arbitration an existing controversy arising out of [a contract involving interstate commerce].” Although this Court has not defined “existing controversy arising out of such a contract,” cases from other jurisdictions upholding agreements to arbitrate under the FAA and the Federal Securities Act because of an existing controversy have involved facts that indicate that at the time the arbitration agreement was entered into, the parties had knowledge or an understanding of the existing controversy. Compare Coenen v. R.W. Pressprich & Co., 453 F.2d 1209 (2d Cir.1972) (<HOLDING>), with De Lancie v. Birr, Wilson & Co., 648

A: holding that the plaintiff was required to arbitrate his claim which accrued before he became bound by the arbitration rules of the new york stock exchange because he was fully aware of the existing claim at the time he became a member of the exchange and became bound by its arbitration rules
B: holding membership in new york stock exchange with concomitant obligation to be bound by arbitration provisions of its constitution and rules sufficient to constitute consent to arbitration of covered disputes whether or not arbitration provisions are specifically incorporated in contract
C: holding that although plaintiff was liable for medical services rendered he was not bound by the amount of the charges listed in the admission contract as he was entitled to question the reasonableness of the charges
D: recognizing that administrative agencies are not bound by rules of evidence
A.