Question

which quote from the story best supports the idea that the story takes place in the past
the new fire engine was a true beauty.
the stations fire horses had been the fastest and strongest in boston.
i was going to miss them. i was pretty sure the firefighters were already missing them.

Explanation:

Fire horses were used in historical fire departments, before motorized fire engines became standard. This detail directly indicates a past setting, unlike the other quotes which do not carry a clear historical marker.

Answer:

The station's fire horses had been the fastest and strongest in Boston.