Which one of these definitions best describe Opportunity Costs?

Alex is studying for his math quiz, but his favorite TV show just started. If he studies for the quiz, he will miss out on watching the show. Alex decides not to watch the show and continue studying for the quiz. What is the opportunity cost of his decision?

Which of these is NOT an example of a need?

Amber was shopping at the mall. She had $80 to spend. She found three items she liked: $75 for a pair of shoes, $70 for a jacket, and $62 for a dress. After shopping for a couple hours, she decided to borrow a pair of shoes from her cousin and to buy the jacket for $70. What was her opportunity cost?

Tom was shopping for a car. He has looked at a Ford, Honda, Toyota, and Dodge. After a lot of debate, he narrowed it down to either the Ford or the Honda. He selected the Ford, because he liked the interior a little better. What was his opportunity cost?