A new study has found evidence of aggressive   behavior in children who drink four or more servings of soft drinks every day. Information for the study came from the mothers of 3,000 5-year-olds. Researchers asked the women to keep a record of how many servings of soft drinks their children drank over a two-month period. They were also asked to complete a checklist of their children's behavior. The researchers have found that 43 percent of the children drink at least one daily serving of soda, and 4 percent of the youngsters have even four or more sodas to drink every day. Shakira Suglia, a famous expert, says they've found that children who drink the most soda are more than twice as likely as those who drink no soda to show signs of aggression. "For the children who consume four or more soft drinks per day, we see more _ behaviors, which make them hard to get along well with others." The aggressive behaviors include destroying possessions belonging to others, taking part in fights and physically attacking people. The researchers have determined the link after considering factors like the child's age and sex. They have also considered other possible influence, such as whether the boys and girls are eating sweets or giving fruit drinks on a normal day. In addition, the researchers have examined parenting styles and other social conditions that may be taking place in the home. Researches are trying to find why young children who drink a lot of soda have behavior problems. An ingredient often found in soft drinks is caffeine, which helps to make people feel energetic. Doctor Suglia suggests that caffeine could cause the 5-year-olds to be more aggressive. Earlier studies of adults have found the highest sugar levels in those who carry weapons   and show signs of negative social behavior. Researchers studied the following aspects of the children except   _  .
age sex games parents
Question: A new study has found evidence of aggressive   behavior in children who drink four or more servings of soft drinks every day. Information for the study came from the mothers of 3,000 5-year-olds. Researchers asked the women to keep a record of how many servings of soft drinks their children drank over a two-month period. They were also asked to complete a checklist of their children's behavior. The researchers have found that 43 percent of the children drink at least one daily serving of soda, and 4 percent of the youngsters have even four or more sodas to drink every day. Shakira Suglia, a famous expert, says they've found that children who drink the most soda are more than twice as likely as those who drink no soda to show signs of aggression. "For the children who consume four or more soft drinks per day, we see more _ behaviors, which make them hard to get along well with others." The aggressive behaviors include destroying possessions belonging to others, taking part in fights and physically attacking people. The researchers have determined the link after considering factors like the child's age and sex. They have also considered other possible influence, such as whether the boys and girls are eating sweets or giving fruit drinks on a normal day. In addition, the researchers have examined parenting styles and other social conditions that may be taking place in the home. Researches are trying to find why young children who drink a lot of soda have behavior problems. An ingredient often found in soft drinks is caffeine, which helps to make people feel energetic. Doctor Suglia suggests that caffeine could cause the 5-year-olds to be more aggressive. Earlier studies of adults have found the highest sugar levels in those who carry weapons   and show signs of negative social behavior. Researchers studied the following aspects of the children except   _  .
A. age
B. sex
C. games
D. parents
Answer: