Stacey has a tendency to repeatedly bite her fingernails when she is in class. her behavior can be called a(n)

Habit

A habit is a routine that is repeated regularly and consistently. These tend to occur subconsciously and in a compulsive way. Old habits are hard to break and new habits are hard to form because repetition conditions our behaviour. In this example, the fact that Stacey bites her nails in class is most likely a habit she does not notice, but that could be altered with a lot of effort.

explanation:

may i ask what challenges?