Isabella Decides to Buy a Dress That Olivia Has for Sale;

Isabella decides to buy a dress that Olivia has for sale; they agree on a price of $20. Which of the following best describes who gains and who loses from the transaction?

A) If the dress originally costs more than $20, Isabella gains and Olivia loses.
B) If the dress originally costs less than $20, Olivia gains and Isabella loses.
C) Both parties expect to gain from this transaction.
D) If Olivia gains from the transaction, Isabella must lose an equal amount.