With no explanation, chose the best option from "A", "B", "C" or "D". U.S. 274, 287, 97 S.Ct. 568, 50 L.Ed.2d 471 (1977)). This element is the most difficult to substantiate. C.f, e.g., Stepanischen v. Merchants Despatch Transp. Corp., 722 F.2d 922, 929 (1st Cir. 1983) (observing that, in a discriminatory discharge case, a plaintiff “will rarely, if ever, be able to produce a ‘smoking gun’ that provides direct, subjective evidence of an employer’s ... intent”). A court must be “particularly cautious about granting summary judgment” in discrimination or retaliation cases, in which one party’s state of mind or intent is “crucial to the outcome.” Id. at 928; see also, e.g., Schwapp v. Town of Avon, 118 F.3d 106, 110 (2d Cir.1997); Geier v. Medtronic, Inc., 99 F.3d 238, 240 (7th Cir.1996); Hossaini v. Western Mo. Med. Ctr., 97 F.3d 1085, 1088 (8th Cir.1996) (<HOLDING>). However, even in such cases, “a plaintiff

A: holding that for state law retaliatory discharge claims the clear and convincing standard is applied at the summary judgment stage  at least when the claim is brought in a federal court sitting in diversity
B: holding that credibility determinations should not be resolved at the summary judgment stage
C: recognizing the difficulty of disposing of issues of discriminatory or retaliatory intent at the summary judgment stage
D: holding that unverified complaints cannot be considered as evidence at the summary judgment stage
C.