In-gyu is going to go camping tomorrow. The bus leaves at 7:30 a.m. In-gyu's mom told him, "You   ⓐ  go to bed early. You have to wake up very early tomorrow."   ⓑ  he went to bed, In-gyu set the alarm clock.

 He arrived at the bus station on time. His friend, Dong-min, got up late and arrived at the station around 8:00. Everybody had to wait for him for about 30 minutes.