so, basically "Meta"="after" physical is well.. physical
so metaphysical is "after the physical". basically, metaphysics deal with questions that can't be explained...by science anyway. It questions the nature of reality in a philosophical way.
some common questions are: does God exists? Is there a difference between the way things appear to us and the way they really are?
is consciousness limited to the brain?
so hat type of poetry sounds like it would be very abstract, and if all of these poet friends did write poems like that then I believe the answer more than likely is
C.) the poet's fondness for abstract ideas.
