According to two factors of Retroactive Interference, RI is caused by two factors: One is unlearning of the first task during the time one is engaged in the second task. What is the second factor?

• A. Unlearning of the responses of second task.
• B. Competition of the first task responses with the second task responses that inhibits the recall responses of the first task at the time of recall.
• C. Inability to recall responses from first task.
• D. Decaying of memory-traces of responses of first task.