The passage suggests that which of the following is true of the structure of cycad cones? A. The structure of cycad cones provides conclusive evidence in favor of one particular explanation of cycad pollination. B. The structure of male cycad cones rules out a possible mechanism for cycad pollination that is suggested by the structure of most female cycad cones. C. The structure of male cycad cones is consistent with a certain means of cycad pollination, but that means is inconsistent with the structure of most female cycad cones.