Many movies involve product placement. For example, the main character in a movie may drink only Dr. Pepper. Companies pay for product placement because they assume that it increases the likelihood that audience members will later buy the product. If a person's shopping is unconsciously influenced by the appearance of a product in a movie, this effect is likely due to existence of the item in:

a. procedural memory.
b. implicit memory.
c. explicit memory.
d. semantic memory