create VM with minimal latency to cloudflare datacenter, which zone?

[max11111111]

both cloudflare and GCP has datacenter at asia-east1(Taiwan) tsa-zone2-456 Chief LY Building Taipei,

but when i try to create an instance it gives me these Zones:

asia-east1-a       asia-east1-b     asia-east1-c

which zone corresponds to the same building Chief LY Building Taipei  ?

thanks