Which of the Following Is the BEST Way to Find

Which of the following is the BEST way to find your most effective speaking voice?

A) Stand in front of a large room full of people and talk as loudly as you can.When your voice sounds loud to those in the back, that's your optimum voice.
B) Close your ears with your fingers and hum up and down the scale until you find the pitch where the hum sounds loudest or most vibrant to you; this is your optimum pitch.
C) Practice speaking with a mouthful of marbles.
D) Use a pitch that is a few notes higher than your normal speaking voice.