Question

How was Rome’s location on a peninsula an advantage for its development?

Herding livestock was easier on the peninsula.
Gathering drinking water was easier on the peninsula.
Farming was easier because peninsulas have fertile land.
Trading was easier because of Rome’s access to the seas.

Answer 1

Trading was easier because of Rome’s access to the seas.

Being on the Italian peninsula (and on the Tiber River near the coast) gave Rome easy access to Mediterranean trade routes and harbors (e.g., Ostia), which boosted commerce, contact with other cultures, and the ability to import resources and project power by sea.