This sentence would probably be a citation in APA style. Citations on research papers are very important since they give due credit to the original owner of the statement. Statements that don't have citations tells the readers that those statements are of the researcher/s alone which would be a problem for them if found out that it wasn't theirs to begin with. This would result to a work of plagiarism which is a grave sin in constructing research papers and is more equated with the act of stealing.
The correct answer is A.
The ideas in this sentence are not coordinated at all. They are merely two sentences linked by the conjunction "and."
In order to coordinate it correctly, a more appropiate conjunction should be added. One possibility would be the word "also."
