In this sentence, we would be understanding the subject verb agreement. The subject of this sentence is impatient which means waiting is not of her liking. This proves that the verb should be in negative sense when comes to waiting. The words "don't" and "doesn't" are negative words. The words “do” and “does” mean the same, that is, “to carry out or to perform an action.” “Do” is used in the first and second persons; “does” is used in the third person. This sentence is in third person thus doesn't is the correct option.

Option C is the correct option.