Roman roads is an adjective phrase. Roman is an adjective that expresses nationality and modifies roads
Military success is an adjective phrase. Military is modifying success.
I don't see any following options to answer your questions.
I think the correct word is, “is”!
Answer:
if you're writing about the summary of a story for let's say,, a reading log. write about the the events that lead to the climate and the outcome after it.
Look at some summaries people have written about movies or books you've read/seen to get an idea. Or I can help you write it.