gearing question

I'm thinking about purchasing, but wasn't sure what to put for terrain (which I assume is a question about how to get the bike). It is hilly where I live, but not sure if realistically I should expect to tackle big hills on this, so otherwise I would take it to flat ground to ride. So should I put hilly, flat, or choose the middle option? Or can you explain the gearing differences? Thanks!

Hi David, Here you can learn more about he gearing options halfbikes.com/how-does-the-halfbike-perform-up-hill Just note that they slightly help on said terrain. Even with the 17T sprocket you'll be able to climb hills up to 8%