Theresa spends 2 hours working instead of watching tv with her friends. the opportunity cost to her of working is
a. The salary earned working per hour.
b. The salary earned working per hour minus the enjoyment of watching TV.
c. The enjoyment she would have received if she had watched TV with her friends.
d. Zero, since Theresa chose to work rather than watch TV, the value of working must have been greater to her than the value of watching TV.