Which of the following statements about development of vocal music behaviors is true?
a. Toddlers begin to impose structure on their improvisations by repeating selected patterns.
b. By the age of 5, many children can use a steady, accurate beat, melody, and rhythm repetitions in their singing.
c. By the age of 3, children can learn songs that are reasonably complex.
d. Babies are able to discriminate among sounds and may sing or hum while engaged in play.