The production of vowel/consonant combinations at 4 to 6 months is called babbling cooing vocalization all of these options

The production of vowel/consonant combinations at 4 to 6 months is called babbling. The period from the 4-th to the 6-th month is called the expansion stage. In this stage the infant is "playing" with the speech mechanism, includes productions of growls, squeals, yells, and raspberries. Some CV like combinations and vowel sounds may be produced.

The correct answer is c