29.

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Item C: there is an adverb and put it at the beginning of the sentence to refer to the National Museum of American Art in Washington, DC mentioned above

Item A/B: There is only one set of subject and predicate, so no need Master-slave conjunction when/where, so item A/B is wrong.

Item D: The point that makes the main clause incomplete.