Roberto and Thomas live in a university hall of residence Roberto values playing loud music at a value of €100. Thomas values Pease and quiet at a value of €150. Which of the following statements is true ?

• A. It is efficient for Roberto to stop playing loud music regardless of who has the property right to the level of sound
• B. it is efficient for Roberto to continue to play loud music
• C. It is efficient for Roberto to stop playing loud music only if Thomas has the property right to peace and quiet
• D. It is efficient for Roberto to stop playing loud music only if Roberto has the property right to play loud music