Here is my 2 cents.
This is an Inference question, therefore, we would need an answer that
MUST BE TRUE, within the same logic as the clause that precedes it. In this prompt, we have
If these initiatives succeed in increasing the demand for solar-power generators in the United States, United States manufacturers will probably maintain significant production levels, since __________.In other words, we have to justify that the US’ initiatives will succeed because of a certain reason
To summarize,
Fact 1 – US produces the most SPG and exports this to Europe
Fact 2 – Eur markets are emerging, and Eur producers are as well
Therefore, US might lose demand in Eur
Fact 3 – Initiatives are underway to increase demand in US.
Need to prove – US will succeed
(A) some United States manufacturers have been substantially increasing their output over the last several years - does not necessarily suggest that demand will be sustained as the Eur producers might overtake US when the markets have established themselves
(B) the efficiency of solar-power generators in converting energy from the Sun into electric power is not improving as fast as it once did- Does not follow in the clause above, if anything, this suggests that the market for solar-power generators as a whole is not feasible in any geographical location
(C) just as European manufacturers enjoy certain competitive advantages in Europe, so do United States manufacturers in the United States- CORRECT. Suggests that the market can be feasible in the US due to the competitive advantage
- Only answer choice that logically follows from the preceding clause. The other answer choices do not support that there can be a market in the US
(D) European governments are currently undertaking initiatives to stimulate the use of solar power within Europe- Does not support preceding clause, also does not suggest a result that may follow from increasing the initiatives in the US. If the same is applied in Europe, then so what?
(E) the current market for solar-power generators in the United States is very limited- It may be true, however, it does not support the phrase that United States manufacturers will probably maintain significant production levels. It does not result to this desired outcome, therefore, we cannot accept this answer.