A group of 45 people attended a ball game. There were twice as many children as adults in the group. Set up a system of equations that represents the numbers of adults and children who attended the game and solve the system to find the number of children who were in the group. A. system15 adults, 30 children B. system30 adults; 22 children C. system22 adults; 30 children D. system30 adults, 15 children