For each of the following situations, identify the opportunity cost involved:

a. Julia decides to volunteer at Amnesty International while she is searching for a job.

b. Victor decides to invest €1 million in a Hungarian pharmaceutical company called Gedeon Richter PLC.

c. Andrea receives $2,000 as a graduation gift and decides to use it to buy a 20-year-old Toyota Corolla.

d. Karl chooses to walk to work instead of taking the metro.

e. After graduating from high school, José decides to work as a waiter instead of pursuing a bachelor’s degree in economics.

f. Magdalena decides to plant some fresh flowers in her garden.

g. Marta decides to hire a professional to clean her apartment.