Read the following lines carefully: 'His words were honeyed lies, / Sweet on the tongue, poison to the soul.' The dominant literary device in these lines is

A paradox is a statement that appears self-contradictory but reveals a deeper truth. 'Honeyed lies' and 'sweet... yet poison' present contradictory qualities — sweetness and poison — coexisting in the same thing, which is paradoxical. While antithesis also involves contrasting ideas, it places them in parallel grammatical structures as opposites; paradox specifically involves an apparent contradiction that contains truth, which is the central effect here.