The question main subject talks about the U.S achieving a zero CO2 economy in the next 30 to 50 years. Wind energy seems to be a viable source of alternative energy and that is extremely likely that the US will be able to do away with CO2.
OPTION A - INCORRECT
Well, we already know the amount of wind energy that is available. The question is how viable is the current wind energy that we have even discovered? Cab we use it? This option is irrelevant.
OPTION B - INCORRECT
We have not finished using wind energy. So, this option has nothing to do with the argument sine we already know that wind energy is enough to meet with our needs. Why look into the sun?
OPTION C - INCORRECT
This option looks popular but I disagree with it. We are talking about achieving zero CO2 economy in 30 years or so. What has current technology got to do with it? For example, iPhone5 will be an obsolete technology in 3 years time, not to talk of 30 years.
OPTION D - INCORRECT
Quite tricky. Not all lobbies are successful. Popular demand can throw lobbies into a tailspin. But we need to do the acid test. if we answer yes to the question, it looks as if we answer no. This makes no difference. Also, it doesn't make the argument stronger in any way. We still need to know if we can even use the wind.
OPTION E - CORRECT
There you go! If the proportion of the wind that is available in accessible area is very low (let say 5%), then that means 95% of the wind is available. This, hence, portray the correct answer.