Controlling your volume, rate, pronunciation and voice are parts of controlling your

a. tone

c. fluency

b. phrasing

d. characterization

Hello, the answer is C - fluency. It cannot be A, because "tone" refers only to volume. "Phrasing" is your choice of words, "characterization" doesn't refer to speaking, so the only answer is "fluency" which encompasses all these parts - volume, rate, pronunciation, voice ...