The answer is B I think so
If you want more information about your city's population, you would most likely use (C) information from the city's official website published in that calendar year.
This source is not only official but is also in the latest time period so that the information listed here will most likely be correct.
Of which book? In lightning their it would be Nancy Bobifit and Smelly Gabe I think.
An adverb clause is a subtype of subordinate/dependent clauses, meaning that it cannot exist on its own, outside of the main, independent clause. In these examples, there are several dependent clauses, in A, C, and D, however, only in C there is an adverb clause 'when we go to the store'.
In the other examples, there are only adjective clauses.
So, the correct answer is C.
