The Sleeper Effect Refers to the Finding That, Over Time

The sleeper effect refers to the finding that, over time, ____. ​

A) people tend to become more and more stubborn about their opinions (and less easily persuaded to adopt alternative points of view)
B) people tend to become more open to, or accepting of, persuasive arguments that they hear repeatedly
C) people tend to become inoculated against (better able to counter-argue) persuasive arguments that they hear repeatedly
D) people tend to forget where (or from whom) they heard a persuasive argument or piece of information