Which of the Following Is an Example of Proactive Interference

Which of the following is an example of proactive interference?

A) You call your new boyfriend by your old boyfriend's name.
B) You call your old girlfriend by your new girlfriend's name.
C) After learning Spanish, you find it difficult to remember your previously-learned Italian verbs.
D) After learning how to play racquetball, you find your old squash stroke is ruined.