If one explorer connects three cities at once, how many trade routes score, and which pair do you pick?

Question

Accepted Answer

Two. Resolve the routes one at a time, covering one city of each with a trading post, so a single explorer joining three cities scores two routes. The rules do not say which pair to choose.

The Guild of Merchant Explorers

If one explorer connects three cities at once, how many trade routes score, and which pair do you pick?