Robert says that his friend Joseph reads a lot of poetry and also exercises for long hours at his local fitness center. Robert asks his friend Grace whether Joseph is more likely to be an English professor or a fitness trainer. Grace replies that Joseph is most likely both. She says that Joseph cannot only be a professor or fitness trainer. This is an example of:
A. the bandwagon effect.
B. the focusing effect.
C. egocentric bias.
D. the conjunction fallacy.