Answer:
the correct answer is "opportunity cost".
the opportunity cost here means the cost of the next best opportunity lost because of spending time at work, this could be 8 hours, 10 hours at work, etc.
the underline point here is that when someone works for, lets say, 8 hours, he or she could have done something else that they enjoy and brings value to them and their family.
but since they are working, they can not engage in that activity. because of this, we call it the opportunity cost! simple right?
Explanation: