Which sentence includes an elliptical adverb clause with an understood word or words?
A. Whitehorse replaced Dawson city as the capital after the gold rush began.
B. Changing its name again as the nineteenth century ended, the Yukon officially became part of Canada in 1898.
C. The capital city, Whitehorse, sits near the Yukon River, where the river becomes navigable.
D. The Yukon has a smaller land area than most other Canadian provinces.