Your school music club is organizing a concert in the auditorium to raise money for a new piano. The ticket costs 15 TL, and your friend Ayşe wants to come with you. There are several rules for this event. Which of the following is a rule that you MUST follow?
A)You can eat and drink only during the break, not during the performance.
B)You mustn't take any photos because it disturbs the performers.
C)You may sing along whenever you like, but you must not use your phone.
D)You mustn't record videos because the club doesn't have permission.