Which two features of lyric poetry are used in robert frost’s “fire and ice”?

some say the world will end in fire,
some say in ice.
from what i’ve tasted of desire
i hold with those who favor fire.
but if it had to perish twice,
i think i know enough of hate
to say that for destruction ice
is also great
and would suffice.

a a single speaker

b the addition of dialogue

c the introduction of characters

d a focus on the speaker’s thoughts

e a plot structure