Use the following information to answer the next three questions: Barney likes to play laser tag. On Friday nights, his favorite establishment has a special: For $20, you can play as many games as you like. The special lasts for 5 hours, and each game lasts for 30 minutes, so Barney can play a total of 10 games if he wishes. Barney has marginal benefits of $25 per game for his first four games played and $10 per game for his next three games played. Beyond that, Barney is so exhausted that his marginal benefit is less than zero. Which of the following best shows the marginal cost of a game of laser tag on a Friday night