Network Technology Setting

I have 3 choices under "Network Technology"settings. I don't know which to choose. I googled and couldn't understand what I was reading. Can I get some direction?

Here are my choices under my AT&T Classic:

1. GSM
2. HSPA+/UMTS
3. HSPA+/UMTS/GSM
4. LTE/HSPA+/UMTS
5. LTE/HSPA+/UMTS/GSM

I live in rural area if that makes a difference. I would think that #5 is the choice??

Do you have LTE in your rural area? I mean 5 is going to default to your top connection available which is fine.

Yes, I have areas of "LTE" so I'll just set to #5. Thanks!