Answer:
b. User-fierce interfaces
Step-by-step explanation:
Based on the scenario being described it seems this is an example of User-fierce interfaces. This basically means that the system in question is not very user friendly, which ultimately makes it very difficult for users to understand, use, and manipulate. This tends to cause the users to get frustrated and ultimately stop using the system as they believe it is too difficult and not worth their time. This is what seems to be happening with the customized learning management system in this question since the 20% of the users quit instantly due to the difficulty of the system.