单选题 According to the article, when a homeowner puts in a solar roof, her worries about blackouts or power rates might be over. Why might that be true?

A、 Solar power may be less expensive and more reliable than power supplied by utility companies.
B、 Her roof won't leak with the heavy solar panels on top of the roof.
C、 Putting in a solar roof is still an expensive preposition.
D、 Super-efficient appliances use less electricity than regular appliances.

【正确答案】 A

【答案解析】文中第二段提到"perhaps，the most reliable power source．The sun．It could mean no more worries about blackouts or power rates"，指出太阳能发电比供电公司更可靠；第九段提到 "eventually，the system should pay for itself，you know 20-years，maybe"，指出太阳能发电将可能比输电网更便宜，因此选A。