Which poetic technique does Robert Browning use in this excerpt from “My Last Duchess”? "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:" such stuff Was courtesy, she thought, and cause enough For calling up that spot of joy. She had A heart—how shall I say?—too soon made glad," A. enjambment B. blank verse C. open form D. end-stopped lines