B. Except as provided in § 3.2-6302, no participant or parent or guardian of a participant who has knowingly executed a waiver of his rights to sue or agrees to assume all risks specifically enumerated under this subsection may maintain an action against or recover from an ox activity sponsor or an ox professional for an injury to or the death of a participant engaged in an ox activity. The waiver shall give notice to the participant of the risks inherent in ox activities, including: (i) the propensity of an ox to behave in dangerous ways that may result in injury to the participant; (ii) the inability to predict an ox’s reaction to sound, movements, objects, persons, or animals; and (iii) hazards of surface or subsurface conditions. The waiver shall remain valid unless expressly revoked by the participant or parent or guardian of a minor. In the case of school-sponsored and college-sponsored classes and programs, waivers executed by a participant or parent or guardian of a participant shall apply to all ox activities in which the participant is involved in the next succeeding 12-month period unless earlier expressly revoked in writing.