You memorize twenty poems while your twin plays video games. Then both of you memorize another poem and you forget it faster. Why did you forget it faster?

A) serial-order effect
B) depth of processing
C) proactive interference
D) encoding specificity

Proactive interference occurs when previously learned information interferes with the ability to learn new information. In this case, memorizing the previous twenty poems could have interfered with the ability to memorize the new poem, leading to faster forgetting. The other options do not seem to be as relevant in explaining the phenomenon described.