Select the most appropriate colocation to fill in the blank.
We came to _______ as we were passing through.

Correct option is B

When someone says "We came to say hello as we were passing through," it means that the person stopped by to greet someone they know as they were passing through a particular place.
 The collocation "say hello" is commonly used to describe the act of greeting someone, especially in informal settings.
 Option (b) is the correct answer.