With no explanation, chose the best option from "A", "B", "C" or "D". exhaustion requirements of the PLRA “where a prisoner plaintiff plausibly seeks to counter defendants’ contention that the prisoner has failed to exhaust available administrative remedies as required by the PLRA.” Specifically, we instructed district courts to conduct a three-part inquiry to ascertain (1) whether administrative remedies were in fact “available” to the prisoner; (2) whether the defendants waived or are estopped from raising an affirmative defense of non-exhaustion of administrative remedies on account of their own actions inhibiting the prisoner from filing a grievance; and (3) whether there exist any alleged “special circumstances” that would excuse the prisoner’s failure to exhaust. Hemphill, 380 F.3d at 686; see, e.g., Giano v. Goord, 380 F.3d 670, 678 (2d Cir.2004) (<HOLDING>); Abney v. McGinnis, 380 F.3d 663 (2d Cir.2004)

A: holding that prisoner justifiably failed to file ordinary grievance when prisoner reasonably believed that department of corrections regulations foreclosed such recourse
B: holding time begins when the prisoner knows  the important facts not when the prisoner recognizes their legal significance
C: holding that a prisoner failed to exhaust his administrative remedies when he did not utilize grievance procedures that permitted waiver of the time limit for good cause
D: holding remedies not available to prisoner where officials failed to respond to his grievance during time period required by regulations
A.