Which of the Following Statements Are Correct Concerning Language Development

Multiple Choice

Which of the following statements are correct concerning language development? (Select all that apply.)

A) Infants initially make vowel sounds using the front part of their mouth.
B) Cooing sounds begin at 2 to 3 months.
C) Babbling begins at approximately 9 to 12 months.
D) By one year words such as "ma-ma" or "bye-bye" begin to emerge.