Which of the Following Best Describes the Expansion of Children's

Multiple Choice

Which of the following best describes the expansion of children's vocabularies between 6 and 10 years of age?

A) Their receptive vocabularies expand at the rate of approximately 10 words per week.
B) Their productive vocabularies expand at the rate of approximately 10 words per week.
C) Their productive vocabularies expand at the rate of almost 20 words per day.
D) Their receptive vocabularies expand at the rate of almost 20 words per day.