Briefly describe the trade-offs involved in each of the following decisions. List some of the opportunity costs associated with each decision, paying particular attention to the trade-offs between present and future consumption.

a. After graduating from university, Victor decides to take a gap year instead of getting a graduate job.

b. Alia decides to practice math every day and take tuitions.

c. Mary takes her dog to the pet shop every week for grooming even though it takes 2 hours of her time and costs £45 for each session.

d. Shanchai is in a hurry to catch her flight. She drives over the posted speed limit on her way to the airport.