Amanda missed her shift at the Keg Diner in order to attend a concert. She paid $40 for the ticket, $10 for parking, and drank $30 worth of alcohol. Had she worked her shift, Amanda would have earned $110. Her opportunity cost of attending the concert is

Select one:

a.

$80.

b.

$180.

c.

$190.

d.

$110.

e.

$0.