In a study, researchers repeatedly measured the intraocular pressure of thousands of teenage volunteers over four years.
The researchers found that intraocular pressure increased more quickly in teenagers who used screens for more than six hours per day.
Conclusion: - Since elevated intraocular pressure is associated with vision impairment, the researchers concluded that heavy daily screen usage contributes to vision impairment.
In order to assess the force of the researcher's evidence for their conclusion, it would be most helpful to know whether
Pre-thinking:
Whether there is a cause-effect relationship between screen usage of more than six hours per day and intraocular pressure increase or just mere correlation.
A. The researchers found that intraocular pressure
increased more quickly in teenagers who used screens for more than six hours per day. Since argument is concerned with rate of increase of intraocular pressure, therefore this statement about absolute values of intraocular pressure is irrelevant.
Incorrect
B. The argument and conclusion is not about overall visual system health but is concerned with visual impairment because of high daily screen usage.
Incorrect
C. This matches our pre-thinking. The statement tries to find out any other cause common with teenagers with high screen usage which results in visual impairment. If yes, then the conclusion does not hold true. If no, then the conclusion holds true.
Correct
D. There may be exceptions in any research. There may be teenagers having less daily screen usage having visual impairment but that does not impact the conclusion.
Incorrect
E. Even if there are other factors leading to visual impairment, this does not weaken the conclusion that heavy daily screen usage leads to visual impairment.
Incorrect
IMO C