What does this mean and what's the answer
consider the location of the italian peninsula. how might this location have the romans control trade in the mediterranean region?

If you look up an old map of the Roman Empire you will see since it's on the peninsula, it's in between the rest of the Roman Empire and Constantinople and Athens, major cities/empires of their time. So it was easier to trade when you're that close to all those other kingdoms.

Hope this helped, I just looked up a roman empire map and said what I think it means.

the density would be a smaller number.