With no explanation, chose the best option from "A", "B", "C" or "D". See U.S. v. Fuentes-Galindo, 929 F.2d 1507, 1509 (10th Cir.1991) (considering these factors in part to decide whether the exceptional circumstances test was met). Although Arnoldo’s parents’ alibi testimony likely can be considered material, the government points out that Amoldo made no showing that his parents were unable to attend his trial. In fact, his mother did travel to the United States to offer her alibi testimony at trial. Regarding Arnoldo’s father, Amoldo offered no proof that his father was unable to travel to the United States other than Arnol-do’s statement that his father was an invalid too ill to travel. See Fuentes-Galindo, 929 F.2d at 1510 (requiring that proponent make some showing that witness would be unavailable to testify at trial); Drogoul, 1 F.3d at 1553 (<HOLDING>). We therefore agree with the district court

A: holding that courts may rely solely on affidavits in granting preliminary injunctions
B: holding that a district court may not consider either hearsay evidence in affidavits or unsworn documents in a summary judgment proceeding
C: holding that proponent may demonstrate unavailability of a prospective deponent through affidavits or otherwise
D: holding that party may not rely on conclusory statements or an argument that the affidavits in support of the motion for summary judgment are not credible
C.