Jenna Is 14 Months Old and Uses Only "Bottle," "No

Jenna is 14 months old and uses only "bottle," "no," "up," "bye-bye," "mama," and "dada" when she talks. However, when her father tells Jenna to get her blue bunny from the bedroom and bring it to him, Jenna quickly runs to get the bunny. What does this example illustrate?

A) Jenna is able to overextend her current vocabulary, when the situation demands it.
B) Jenna likely has a speech impediment.
C) Infants have difficulty pronouncing phonemes they have never heard.
D) Toddlers' receptive vocabularies are larger than their productive vocabularies.