D. The appearance of the odd people
It would be D) carbon dioxide (I took the test haha).
<span>I am pretty sure that the following which is a moderate to vigorous sport that a student can participate in at school without teammates is the option : </span><span>Tennis. I choose this option because, a you know, it is one of kind of sports which can include single player. So, I bet it is correct. Do hope you will agree with me!
</span>Regards.