
I find A as the best option.
Reason: The argument behind conclusion is that less ppl are purchasing TV 'cause TV' has become too costly to purchase for a typical consumer.
televisions are becoming too expensive for the typical consumer. As a result, the average number of residents per household will again surpass the number of televisions.
So to strenghten the argument, correct answer will suggest that ppl are unwillingly refraining from purchasing new TV set ( not by choice).
Now look at options:
B. Too weak. At best it suggests that number of resident is increasing, nothing else. OUT
C. Eyecatcher for sure BUT..
First, it doesn't suggest that ppl are getting same kind of entertainment and information services as they get on TV.
TV word isn't even mentioned in this option.
Second, C suggest that ppl are not buying TV sets by choice not because they cant afford it ( money factor).
Apart from that it doesn't mention that increase in the sale of new devices will continue in future and question ask you to prove that in future number of viewers will surpass number of TV set.
D. Crap.
E. Again crap.
Now my selection, A.
Number of household parties has increased 300%.To me, It is too large an increase to assume that this is because of some trend. It suggests that ppl are very much willing to watch shows on TV sets but since they dont have one they are attending such household parties.
Anyway, this is my reasoning. If OA isn't A, and if I encounter this question on GMAT then I would surely have atleast one wrong that means no 800 :p