True!The both talk about the overall moral of the story.
For an example
THEME Central
Jealousy. Mya always wanted the same
thing Layla had.
Hard work pays
Off. Tyianna worked for hours to
earn money.
Bravery||||Even though Tim was afriad Of heights he still climbed up the mountain.
So basically a theme is telling you something all in one word and a central idea is giving you details.
Hopes this helps.
I have never read what you are asking, but just by looking at it, I would assume that he is stereotyping Dutch people, because he is calling Black Dog an insult, which is "son of a dutchman".
Answer:
Your answer is correct, it's D! Hope this helps~~~ ^^ :333 <3333