What Determines Which Data Center I Connect To?

I’m just west of Nashville, TN using AT&T VDSL2 as my ISP. I’m currently using Cloudflare public DNS for both IPv4 and IPv6. When I check, I am connecting to the Atlanta data center. Is there any reason why I’m not connecting to the closer Nashville, TN datacenter instead for my DNS queries?

Usually the issue in this case is routing due to the ISP, they may not interconnect there or they may force the IP ranges for Cloudflare there.