In "my last duchess" by Robert Browning, the poet uses run-on lines to express long, complex ideas and emothions. Option C is correct.
A run-on line is called enjambment and it is a is incomplete syntax at the end of a line; the meaning runs over from one poetic line to the next, without terminal punctuation. Lines without enjambment are end-stopped.
This resource cause a delay of meaning which creates a tension that is released when the word or phrase that completes the syntax is encountered.