If a 2-Year-Old Child Uses the Word Car in a Situation

If a 2-year-old child uses the word car in a situation where her dad is washing the car,again when she is sitting in the car,and yet again when she is looking out the window,each time with different inflection,what does research indicate that this toddler is probably doing?

A) expressing three different messages about the car
B) simply practising use of the new label that she has learned
C) overextending the use of the word car
D) underextending the use of the word car