Final answer:
'The Poison Tree': The speaker in the poem embodies moral duality and seeks revenge and forgiveness.
Step-by-step explanation:
In the poem 'The Poison Tree,' the speaker is depicted as both good and evil, embodying moral duality. The speaker seeks revenge and forgiveness (a), as expressed through the metaphorical language of the poem. While the speaker may be kind to friends and hostile to foes (c), it is the internal conflict between good and evil that is the central theme of the poem.