Hi mates,
this is a very tough one!!

IMHO
DA out: it's a fact that people who own a computer see less television than people who don't own one, but this answer is questiong this fact.
B out: national average doesn't have nothing to do here
C out: this answer supports the current idea, which is asked to be clarified.
E out: this answer syas the oppsite that the sentence says: that people with coputer see less television
I hope I'm right
OA?
What level do you think this question belongs to?
Cheers