What does the last paragraph conclude?

Question

Answer

It refutes the results of the studies about the function of social networking to students

Answer

It rebuts the conclusion of several researches concerning the function of social 
networking to students

Answer

It cites studies that validate the goodness of social networking to students‘  learning

Answer

It remains dubious as to whether social networking brings about any good to students

Answer

It hardly accepts the positivity of social networking to students

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