I know for a fact that either B. or C. is correct. I think C.
I think the answers are 10= essence 11= A 12= B 13 = C
The park or beach because you can relax and enjoy the view you and in the park you can walk and enjoy the nature and kick the stress you out of your mind and focas on relaxing.
The answer should be an object of a verb. The bold words are neither a proposition(which is a word that expresses a relation to another word, like "after" or "next to") or the subject. The subject in this case would be the city of Washington.
