Karen Hollis (1984) has demonstrated that male blue gouramis (Trichogaster trichopterus) that have been classically conditioned to a signal that predicts an encounter with a rival

A) are less successful in aggressive contests but recover once the effects of the conditioning have worn off.
B) are more successful in aggressive contests and maintain their advantage in later contests.
C) are more successful in aggressive contests but may lose their advantage in later contests.
D) produce results that depend on whether or not a gravid female is present.