in that paragraph, the expression Mounting evidence could be a bit confusing, but it indicates that there's been reaserch about it before, and that it all points in the same direction, the more research proving the same point means the data is convincing. The answer is D.
Answer:
Nonstandard forms of English are valid, complete languages.
Explanation:

Sentence is a group of words which makes a complete sense.
Answer:
Its either the first option (on the left)
or the bottom option on the left
(other words its either "A study found that playing certain games gave students more confidence" or "video games have benefits in the classroom besides grabbing students interest"
To show that you have considered different point of view!!!! AAAPPEXXXXXX