In Dickerson Et Al

In Dickerson et al.'s (1992) study on using cognitive dissonance theory to increase water conservation, which of the following groups took the shortest showers?

A) Participants who both signed a flyer stating that they take short showers AND were asked questions about water conservation.
B) Participants who signed a flyer stating that they take short showers OR were asked questions about water conservation.
C) Participants who did not sign a flyer stating that they take short showers nor were asked questions about water conservation.
D) Both a and b were equally short.