How Has Caffeine Been Found to Impact the Persuasion Process

How has caffeine been found to impact the persuasion process?

A) A person who has ingested caffeine is LESS likely to be persuaded by the central route than someone who has not ingested caffeine.
B) A person who has ingested caffeine is JUST AS likely to be persuaded by the central route as someone who has not ingested caffeine.
C) A person who has ingested caffeine is MORE likely to be persuaded by the central route than someone who has not ingested caffeine.
D) This question has not yet been researched.