With no explanation, chose the best option from "A", "B", "C" or "D". case, based on the materials submitted by the defendants in support of their summary-judgment motion, there is no dispute that, for the purposes of the Equine Act, Stepping Stone and Huguley are “equine activity sponsors”; that Croxton is an “equine professional”; or that the Estes, A.G.E., and the defendants were engaged in “equine activities” on June 27, 2010. The defendants properly supported their motion for a summary judgment with materials establishing their claims of immunity. Therefore, unless Estes can establish either that the immunity defense is not applicable or that an exception to that defense is applicable, the summary judgment in favor of the defendants should be affirmed. See, e.g., Ryan v. Hayes, 831 So.2d 21 (Ala.2002) (citing Ex parte Davis, 721 So.2d 685 (Ala.1998))(<HOLDING>). Estes does not contest that the Equine Act

A: holding that qualified immunity is not merely immunity from damages but also immunity from suit
B: holding that once a defendant established that stateagent immunity attached the burden shifted to the plaintiff to establish that an exception to the immunity was applicable
C: holding that the burden is on the defendants to establish the existence of absolute legislative immunity
D: holding that defendant is entitled to qualified immunity because plaintiff failed to allege the violation of a clearly established constitutional right
B.