Which Is the BEST Example of Stimulus Generalization

Which is the BEST example of stimulus generalization?

A) Bonnie learned to choose and wear coordinated outfits but after one month she would only select red outfits.
B) Jim was taught to say "hello" and continues to say "hello" to his trainer.
C) Ricky became more productive in math and simultaneously his reading improved.
D) Tim learned to ask for help from his teacher and now can ask a fellow student for help.