A four-year study of 200 college students found that those who drink heavily and started drinking at an early age demonstrate poor decision-making skills, just like long-term, chronic  alcoholics. Researchers at the University of Missouri-Columbia believe early onset binge drinking negatively affects psychological development. The researches examined college students between the ages of 18 and 22. After three years, they tested them using the Iowa Gambling Test, which measures the tendency to make immediate (disadvantageous) or long-term (advantageous) choices. Based on the students' reported drinking habits, they were grouped into four categories: low binge drinkers, moderate binge drinkers, increasing binge drinkers and stable or high binge drinkers. "Students in the stable or high alcohol use category, who had longer histories of binge drinking, made riskier and less advantageous choices, which reflect problems associated with planning for the future," the researchers reported. The study also found that only students who started binge drinking when they were younger showed impairment on the task. "There is reason to think that heavy binge drinking during adolescence, when the brain is still rapidly developing, may have some negative legacy   on psychological development," said Kenneth J. Sher of MU's Midwest Alcoholism Research Center in a news release. "The interesting thing is that if we were to just look at binge drinkers and how impaired they are in the decision-making process as juniors, we'd really be obscuring  the important issue, which is how long they've been binge drinkers and / or how early they started." What Kenneth J. Sher says suggests that   _  .
he is quite clear about what the important issue is if binger drinkers started late, there would be no bad effect the important issue is how impaired the students are in decision-making only early binge drinkers will have their decision-making ability affected
Question: A four-year study of 200 college students found that those who drink heavily and started drinking at an early age demonstrate poor decision-making skills, just like long-term, chronic  alcoholics. Researchers at the University of Missouri-Columbia believe early onset binge drinking negatively affects psychological development. The researches examined college students between the ages of 18 and 22. After three years, they tested them using the Iowa Gambling Test, which measures the tendency to make immediate (disadvantageous) or long-term (advantageous) choices. Based on the students' reported drinking habits, they were grouped into four categories: low binge drinkers, moderate binge drinkers, increasing binge drinkers and stable or high binge drinkers. "Students in the stable or high alcohol use category, who had longer histories of binge drinking, made riskier and less advantageous choices, which reflect problems associated with planning for the future," the researchers reported. The study also found that only students who started binge drinking when they were younger showed impairment on the task. "There is reason to think that heavy binge drinking during adolescence, when the brain is still rapidly developing, may have some negative legacy   on psychological development," said Kenneth J. Sher of MU's Midwest Alcoholism Research Center in a news release. "The interesting thing is that if we were to just look at binge drinkers and how impaired they are in the decision-making process as juniors, we'd really be obscuring  the important issue, which is how long they've been binge drinkers and / or how early they started." What Kenneth J. Sher says suggests that   _  .
A. he is quite clear about what the important issue is
B. if binger drinkers started late, there would be no bad effect
C. the important issue is how impaired the students are in decision-making
D. only early binge drinkers will have their decision-making ability affected
Answer: