Answer:
D. It is evident that she did not maintain any of the original learning in her long-term memory
Step-by-step explanation:
Memory is defined as the psychological system by which the human brain receives information from the senses and stores it away for later use.
Memory can be short term (retrieved shortly after learning), and long term (retrieved after a long time).
In the given instance Mitzi learned the concept of classical conditioning within 60 minutes. Three weeks later, she realized it took her about 60 minutes to understand it once again.
This means that she did not maintain any of the original learning in her long-term memory for the information to be easily retreived