The old post office was dirty and proved to be difficult to enter and to exit. You are changing was

A. no change
b. were

A. no change

can you be more do you have options/ if so, you can put it in the chat or edit your question (

well, i hope this at least : ) :

noun: a temporary state of mind or feeling.

adjective: (especially of music) inducing or suggestive of a particular feeling or state of mind.

examples:

hope this ! : )

i believe that the answer is b! i hope i out!