When Will Children Typically Begin Experimenting with Different Sounds

When will children typically begin experimenting with different sounds?

A) Infants begin making simple sounds and by 12 months of age can say a handful of words.
B) This occurs by 8-9 months of age.
C) This occurs by 6 months in the form of coos.
D) Usually sound play comes after age 2, entering toddlerhood.
E) Sound experimenting is mostly dependent on a child's personality and temperament.