Cosmo Is Convinced That His Accountant Is Addicted to Drugs

Cosmo is convinced that his accountant is addicted to drugs. To determine whether he is correct, Cosmo asks his friends if the accountant sniffs a lot, uses slang when he speaks, or frequently excuses himself to use the men's room-three behaviors Cosmo believes are characteristic of those with drug addictions. Cosmo's methods illustrate

A) the false-consensus effect.
B) a self-fulfilling prophecy.
C) confirmatory hypothesis testing.
D) the trait negativity bias.