Thaïs spends a semester abroad in Japan immersing herself in the culture and taking intensive language classes. By the end of her trip, she is proud of her proficiency in Japanese and is eager to continue practicing her Japanese conversation skills. However, a few years after returning to the United States and not having been around anyone who speaks Japanese, Thais unfortunately can barely remember any of the Japanese she previously learned. Her experience MOST reflects the process psychologists refer to as:

A. pseudoforgetting.
B. memory decay.
C. retroactive amnesia.
D. proactive interference.