A sleeper effect occurs when:
a. distraction interferes with the ability to pay attention to a persuasive message.
b. people fall asleep during exposure to a persuasive message.
c. a persuasive message from a non-credible source becomes more persuasive over time.
d. persuasion occurs in response to subliminal stimuli.

a. distraction interferes with the ability to pay attention to a persuasive message

Explanation:

A sleeper effect is the persuasion effect that is impacted by the increase in the delay of the occurs when a communication shows no immediate persuasion effects and this when the message is accompanied in a discounting cue.Also relates to the process of the forgetting that states that the cue disappears and goes away and becomes unavailable in the memory over the time and disassociation starts.