Some one plz help.

“Is there no moon?
And is this springtime not
the spring
of times gone by?
Myself alone remaining
still the self it was before?”
—Ariwara no Narihara,
quoted in Christian Science Monitor

“That autumn has come
appears nowhere with clarity
to the observing eye:
It is a new sound in the wind
by which we are somehow made aware.”

According to the poem by Ariwara no Narihara, what stays the same as the seasons go by?
a.
the moon
c.
the self
b.
the springtime
d.
the poem