Which poetic technique does robert browning use in this excerpt from “my last duchess”?

The poetic technique that poet utilized in his literary work "My Last Duchess" is enjambment.

That technique means the thought found in one line of the literary work doesn't finish with the tip of that line, however rather continues into the subsequent line. There aren't any harsh endings of thought at the tip of 1 line.

the narrator closes the lantern tightly so the old man is

not awakened by the bright light

explanation:

c) eager anticipation.