Monotone means having no expression in your voice, no anger, no happiness, no interest. This word would affect the tone by giving the reader the feeling that he just doesn't care about what is going on/ what he's talking about. I hope this helped!
I would say:
<span>C.
present participle
I could be wrong though</span>
Answer:
A. (Browning, R 23) and (Browning, E 101)
Explanation: