First person is singular, the past of it will be the pronoun verb
It would have to be: Make sure that you have clearly explained what happened, how it happened, and why.
<h2>Answer:</h2>
According to me the statement that best explain the difference between Mr. Dussel's and Mr. Frank's viewpoint is
C. Mr. Dussel believes the Dutch are good people, Mr. Frank does not.
Because in this situation they are actually having a different opinion or point of view about Dutch. So, it explain best the difference between their point of view.
Would you like some water?
No, thanks
Would you like some peas?
Yes, please
Would you like some cheese
Yes, please
Would you like some apple?
No, thanks
Would you like some pasta?
Yes, please