Question

Which of the following are you not likely to find on a historical map of World War 2

Answer 1

A. Key batteles
B. Lines of political division
C. Time frame
D. Unsung heroes

Answer 2

Maps don't usually show people unless it's an interactive map. Those are cool.
But the question says historical map. I'm thinkin' they are talking about a paper map. Which could show them, But of the choices, I'd go with the heroes who don't have songs.