Which of the Following Individuals Is Displaying Superstition

Which of the following individuals is displaying superstition?

A) Every time Jorge hears a certain tune, he thinks of the night he proposed to his wife. Today he heard a similar tune, which also made him think of the night of his proposal.
B) The last time Rose hit a homerun, she patted her batting helmet just before taking her swing; now she pats her batting helmet every time she enters the batting box.
C) Ian was conditioned to laugh at the sight of a clown, but over time his response weakened. He no longer laughs when he sees clowns.
D) After being bitten by a brown dog, Allison is afraid of all brown dogs.