in·ter·ur·ban
[ˌin(t)ərˈərbən]
ADJECTIVE
existing or traveling between cities.
"the target is to reduce congestion on interurban roads" · [more]
NOUN
NORTH AMERICAN
historical
a railway or train operating or traveling between cities.
"the interurban provided a new predictable and comfortable way to travel"
I think it's B :)
