Which of the following is the best example of a trade-off?

A consumer has three hours on a Friday evening and wants to do something fun in that time.
A consumer has $50 but wants to buy two pairs of shoes that each cost $50.
A consumer has $50 to spend but must choose between buying a new $50 jacket or going out for a $50 dinner.
The owner of a construction company has 20 workers who help build a house.

A consumer has $50 to spend but must choose between buying a new $50 jacket or going out for a $50 dinner.