I think it's D because it's the main thing
Main clauses express a complete thought and appear in compound, complex and compound-complex sentences. Therefore, the correct answer is all of the above. A compound sentence is made up of two independent clauses which are joined by a coordinating conjunction. A complex sentence is made up of an independent clause and a dependent clause which are joined by subordinating conjunction. A compound-complex sentence is made up of two or more independent clauses and one or more dependent clauses.
It would be dialogue because there are no stage directions and this is not narrating anything.
Amsterdam during the Second World War?