Answer:
A. enjambment
Step-by-step explanation:
The poetic technique that Robert Browning uses in the excerpt from "My Last Duchess" is enjambment.
Enjambment means the continuation of a sentence without pause after the end of a line, couplet or stanza or it means that the thought in one line of poem does not end in that line but still continues in the next line.
"Of joy into the Duchess' cheek: perhaps Frà Pandolf chanced to say "Her mantle laps Over my lady's wrist too much," or "Paint Must never hope to reproduce the faint Half-flush that dies along her throat:"