This familiar arena as it is not just a piece of question but also an information that could affect our lives and physical fitness ability

Option A - Incorrect
There is a problem with a sentence flow here. The use of "but" means a contrary view or subject is being discussed. Meanwhile, The first line of the underlined statement is being supported by the last three lines so, "but" is not needed here and its confusing.

Option B - Incorrect
Still the same as in A above. The flow of the first part is inconsistent with the second part. it should have in the real sense strengthened it but it does no appear to have done that.

Option C - correct
This is more appropriate. Looking at it from the position of strength, you'd realise "although" is a bit more positive that "but", it shows that the second part strengthens the first.

Option D - Incorrect
The assertion by the author here is not different from those of option A and B. Still unchanged.

Option E - Incorrect
The sentence structure here is seemingly inapplicable and renders the statement inexcusable.