जगातील सर्वात ऊर्जा-कार्यक्षम शहर कोणते आहे? A. व्हँकूवर B. रेक्जाविक C. डेन्मार्क D. माल्मो

Reykjavik, Iceland's capital, runs almost entirely on renewable geothermal and hydro power and was rated the most energy-efficient city, as per the official key. (Denmark is a country, not a city.)