In the Case of King George VI, Stuttering Was Alleviated

In the case of King George VI, stuttering was alleviated by singing, rather than speaking. Why did this work?

A) Singing actually didn't work. The king's stuttering was alleviated through the use of electric shock therapy"
B) Singing allowed the king to practice his articulation, and this eventually led to less stuttering"
C) Singing activated the auditory areas of the brain, providing feedback"
D) Singing lowered the amount of activity in the premotor cortex, allowing for the king to slow down the movements of his mouth"