Question

In this poem Tennyson refers to both Ulysses and Achilles what is this technique called in literature

Answer 1

The correct answer is:

B) allusion

Answer 2

In the poem, Tennyson refers to both Ulysses and Achilles. This technique is called B. allusion in literature.
When you use allusion, you are referring to people or places outside of the novel or essay, or whatever it is you are writing. And since Ulysses and Achilles are not Tennyson's characters, he is alluding to them when he mentions them in his poem.