Today you are planning to see a film and you can attend either of two cinemas. You have only a small budget for entertainment, so prices are important. You have attended both cinemas recently. One charged €5 for admission; the other charged €7. You habitually buy popcorn in the cinema – each cinema charges €3. The films now being shown are equally attractive to you, but you are virtually certain that you will never see the film that you reject today. Identify the relevant costs. Explain your answer.