Everything/anything

[Belly T]

Chicago is the city which ____ could be possible
a) everything
b)anything
Could you show me the correct answer and explain why it is right?

[Casiopea]

Shouldn't the relative pronoun be in which or where?

My pick is b) anything. It's non-specific, whereas choice a) everything is specific. Mind you, both a) and b) work in that context; however, anything could be possible/anything can happen is more common/commoner. It means, the unknown could happen, Cf. everything could be possible; everything you dreamed of happening could happen.


All the best.