Thinking Skills Assessment: Entrance Exam Sample Questions
Contrary to what many people claim Facebook cannot improve our experience of friendship. It may make it easier to increase our number of contacts but there is a limit to the number of people we can keep in mind and with whom we can have a meaningful relationship.  The number is 15 and is set by the size of our brains.  Moreover the quality of relationships depends on the amount of time we invest in them.  If we increase our number of friends the time devoted to maintaining each relationship will decrease and our emotional connection with each person will decline.  Meaningful relationships are about being able to engage in activities with others face to face.  Communication via the internet is no substitute.

Which one of the following best expresses the main conclusion of the above argument? 
Correct!
E
Facebook cannot improve our experience of friendship.
Explanation
Not all arguments give their conclusion at the end.  In this case, the first sentence is the main conclusion.  The rest of the text is providing the reasons for the conclusion.  In this case there are no obvious indicating words; so, you must think about what the argument is trying to persuade you of by considereing the content of the sentences. 

A is a premise denying that the sheer volume of friends on Facebook is enough for Facebook to be an improvement.
B is a premise.
C may not be true; or, it is at least debatable; but, this does not mean it is the conclusion.
D is a premise.