It is too biased; this research question contains an opinion and cannot be answered through research.
Explanation:
The research question is biased because it is based on the author's opinion about adolescents and physical activities. The author does not show any data that made him come to this question, so we know that this is his / her opinion. It would be different if the author asked the question as follows: "Previous research shows that 80% of high school students do not spend enough time doing physical activities every day. Why does this happen?" This way the author would show that the question was asked based on proven data and not on an opinion.
From this we can conclude that the right answer to this question is "It is too biased; this research question contains an opinion and cannot be answered through research."