After the first word is spoken,

A) vocabulary immediately grows at an extremely rapid pace.
B) further increases in vocabulary occur very slowly and steadily.
C) vocabulary growth is slow for several months and then speeds up dramatically.
D) no further vocabulary growth takes place until around 18 months.

After the first word is spoken, vocabulary growth is initially slow for several months as the child is learning the meanings of words and how to use them. However, around 18 months, vocabulary growth speeds up dramatically as the child is able to learn and use new words more easily. Therefore, option C is the best choice as it describes the initial slow growth followed by a dramatic increase in vocabulary.