Question #N670

The ancient city of Petra, in Jordan, was carved into the sandstone cliffs by the Nabataeans, a nomadic people who settled there in the 4th century BCE. Petra was a major center of trade, and its architecture, especially the Treasury, a temple carved into the rock face, is known for its elaborate detail and impressive scale. In 1985, UNESCO designated the city a World Heritage Site, however, the ancient city is threatened by the effects of climate change and tourism.

Which choice most effectively combines the sentences at the underlined portion?
A. In 1985, UNESCO designated the city a World Heritage Site, though the ancient city is threatened by the effects of climate change and tourism.
B. In 1985, UNESCO designated the city a World Heritage Site, the ancient city is threatened by the effects of climate change and tourism.
C. In 1985, UNESCO designated the city a World Heritage Site, but the ancient city is threatened by the effects of climate change and tourism.
D. In 1985, UNESCO designated the city a World Heritage Site; the ancient city is threatened by the effects of climate change and tourism.